Barton S . Alexander Barton Stone Alexander ( September 4 , 1819 – December 15 , 1878 ) was an American engineer commander during the American Civil War who rose to the brevet rank of brigadier general in the regular army . He was a graduate of the U . S . Military Academy at West Point and served in the United States Army ' s Corps of Topographical Engineers , which at times was both a part of and separate from the United States Army Corps of Engineers . After graduating from West Point as a second lieutenant in the Class of 1842 , he served in the Mexican - American War , building fortifications to protect American supply lines in the advance on Mexico City . After the end of the war , he was stationed in Washington , D . C . , where he served as architect for the Scott Building and Quarters Buildings at the U . S . Soldiers ' Home and took over the completion of the Smithsonian Institution Building after dissatisfaction with the pace of the first architect caused him to be dismissed . After the completion of the Smithsonian in 1855 , he traveled to New England , where he supervised the rebuilding of the Minot ' s Ledge Light house , a project widely considered to be one of the most difficult to be attempted by the U . S . Government up to that time . During the American Civil War , he served as an advisor to the Engineering Brigade of the Army of the Potomac and became chief engineer of the defenses of Washington , D . C . Following the conclusion of hostilities , he served as chief engineer of the Military Division of the Pacific , making him the head engineer for every military construction project on the West Coast . In later years , he persuaded the U . S . government to acquire Pearl Harbor from the Kingdom of Hawaii and supervised numerous irrigation and land reclamation projects in California ' s central valley . He died on December 15 , 1878 , in San Francisco , California . Pre - Civil War . Alexander was born in Nicholas County , Kentucky , He entered West Point in the fall of 1838 . Alexander was a diligent student , and corrected an entering weakness in mathematics to graduate seventh of 56 cadets in the Class of 1842 . Between 1843 and 1848 , he worked on several fortification projects along the East Coast of the United States , including Forts Pulaski , Jackson , and the defenses of New York City . In 1848 , he participated in the Mexican - American War as a second lieutenant of engineers , helping build defenses to protect American supply lines as Winfield Scott ' s army advanced on Mexico City . After the conclusion of the war , now - First Lieutenant Alexander returned to West Point for a four - year assignment as Treasurer and Superintending Engineer for the Cadets ' Barracks and Mess Hall . In 1852 , Alexander was assigned to Washington , D . C . , where he assisted in the design and construction of several government buildings . The first of these was the Scott Building of the U . S . Soldiers ' Home , now known as the Armed Forces Retirement Home . The building was named for General Winfield Scott , who donated $ 100 , 000 for the establishment of the Soldiers ' Home in 1851 . It served as the central focus of the complex , and still stands today . Constructed in the Romanesque Revival style , the Scott Building features a round - arched motif utilizing white Vermont marble . At the same time as his work on the Scott Building , Alexander was asked to take up the challenge of completing the Smithsonian Institution Building , the progress of which had bogged down under architect James Renwick , Jr . In August 1853 , Alexander accepted , and by 1855 , the Smithsonian Building was complete . During construction , Alexander slightly altered Renwick ' s original design by placing the Smithsonian ' s main lecture hall on the second floor . The change allowed for superior acoustics and a wider space than could be found on the first floor . To support the large lecture hall and the central core of the building , Alexander arranged for the installation of fireproof masonry - encased iron structural columns . These would prove their value on January 24 , 1865 , when a fire broke out on the roof above the lecture hall . The resulting blaze destroyed the hall and damaged much of the rest of the structure . Thanks to the fireproof columns , however , the Smithsonian building did not collapse . Minot ' s Ledge Lighthouse . Following his work on the Smithsonian , but before the Scott Building finished construction , Alexander traveled to New England , where he was assigned to a project at the entrance of Boston harbor . That project , the rebuilding of Minot ' s Ledge Light house , was widely considered to be one of the most difficult to be attempted by the U . S . Government up to that time . Designed by Brigadier General Joseph Totten , head of the U . S . Army Corps of Engineers , the lighthouse was intended to replace a structure that had been destroyed in an 1851 storm . With multiple ships wrecking on the ledge annually , the need for a lighthouse was crucial . Appointed superintendent of the lighthouse construction in April 1855 , newly promoted Captain Alexander modified Totten ' s design in accordance with conditions at the site . Because the site of the lighthouse was continually awash , except at low tide and calm seas , the work of preparing the interlocking granite blocks and iron framework of the lighthouse was done at nearby Government Island , adjacent to Cohasset , Massachusetts . The work progressed slowly , hampered by the partially submerged nature of the site , violent storms that wracked the area , and the fact that preparatory work had to be done away from the building site . During construction , a particularly violent storm hit the construction site , sweeping away much of the iron framework intended to support the stone shell of the lighthouse . Captain Alexander was discouraged , reportedly saying , " If wrought iron won ' t stand it , I have my fears about a stone tower . " Those fears were allayed when news reached Alexander that the damage had been due to a ship striking the lighthouse , rather than from just the storm alone . Work recommenced on building the lighthouse , and the final stone was laid on June 29 , 1860 , five years after Alexander and his workmen first landed at the ledge . The final cost of about $ 300 , 000 made it one of the most expensive lighthouses in United States history . Civil War . Following the completion of the Minot ' s Ledge Lighthouse project in 1860 , the secession of South Carolina and the beginning of the American Civil War allowed Alexander to put his skills to military use for the first time since the Mexican - American War . On May 24 , 1861 , he was among several hundred engineers who marched into Virginia to begin building fortifications to protect Washington , D . C . , which was located on the border between the Union state of Maryland and the Confederate state of Virginia . In July 1861 , the force that had marched into northern Virginia on May 24 found itself opposed by a large Confederate States Army force that had marched up from the south . In the haste to meet the Confederates in battle , Alexander found himself serving as an infantry officer and was assigned to the 1st Division of the Army of Northeastern Virginia , under the command of Brig . Gen . Daniel Tyler . It was a situation common to the young Union Army , which found itself short of experienced officers . Many engineer officers building defenses south of Washington were assigned to a regiment or division during the First Battle of Bull Run . Alexander received a brevet to major in the regular army for his service during the battle . Engineering Brigade . Following the defeat at Bull Run , the Union Army retreated back to the defenses of Washington . Throughout the remainder of 1861 , the newly named Army of the Potomac , under the direction of its new commander , Maj . Gen . George B . McClellan , expanded and improved the improvised defenses that had been built in the seven weeks between the occupation of Northern Virginia and the Battle of Bull Run . New regiments arrived in Washington daily , and were placed in camps in and around the city . Two of these new arrivals — the 15th New York Volunteer Infantry Regiment and the 50th New York Volunteer Infantry Regiment — were designated " engineer regiments " and placed under the superintendence of Lt . Col . Alexander . Following a brief training period under Alexander , the two regiments were declared to be an " Engineering Brigade " and placed under the command of Brig . Gen . Daniel P . Woodbury . Woodbury ' s brigade was itself under the command of Brig . Gen . John G . Barnard , chief engineer of the Army of the Potomac . Alexander remained attached to the Engineering Brigade as an assistant . Alexander continued in this role during the Engineering Brigade ' s deployment with the Army of the Potomac during the Peninsula Campaign , several times performing ably under hostile fire . He was appointed a brevet lieutenant colonel for his service at the Siege of Yorktown , as of May 4 , 1862 . Following the abandonment of the campaign and the return of the Army of the Potomac to northern Virginia , General Barnard , now chief engineer of defenses of Washington , D . C . , requested Alexander serve as his aide - de - camp . Alexander accepted and served in that capacity throughout 1862 . When the Topographical Engineers and the Army Corps of Engineers were merged on March 3 , 1863 , Alexander ( whose permanent U . S . Army rank was captain until this time ) was promoted to major , while retaining his brevet ( honorary ) rank of lieutenant colonel . In August 1863 , as part of his duties as aide - de - camp to General Barnard , Alexander was named as a member of a board of military officers who would examine the defenses of Washington and suggest improvements as needed . The board , created by the Secretary of War , Edwin M . Stanton , was designed to replace a civilian board that he had created in 1862 . In a November 1863 meeting , this board recommended final allotments of guns and ammunition for the forts protecting Washington , D . C . , thus establishing the number of guns that would be in place during the Battle of Fort Stevens eight months later . Defenses of Washington , D . C . . On June 1 , 1864 , General Barnard was named the chief engineer of the Armies in the Field by Lt . Gen . Ulysses S . Grant . This move made Alexander the chief engineer for the defenses of Washington , filling the position vacated by Barnard ' s departure . It was a role he would take until well after the surrender of Robert E . Lee ' s Army of Northern Virginia on April 9 , 1865 . The appointment was largely a caretaker role , as the final number of guns and forts had been established by the 1863 commission , and the Union Army ' s success in the field meant that no major force could threaten Washington . The only exception to this came in late July 1864 , when Confederate forces under the command of Lt . Gen . Jubal A . Early attacked Washington ' s defenses from the north during the Battle of Fort Stevens . Following the conclusion of the war , Alexander presided over the drawdown in U . S . Army forces in Washington and the gradual decommissioning of the forts surrounding the city . On May 9 , 1865 , Alexander was ordered to stop work maintaining and improving the forts surrounding Washington as part of cost - cutting measures . Alexander , not wishing to see Washington return to its defenseless pre - war state , recommended that some forts be continually maintained in order to preserve them for future needs . The recommendations were accepted , but Alexander ' s ability to follow through on them was limited by an August order to " not incur expenses for hired labor " and the inability of the chief engineer of the District of Washington to furnish the large numbers of enlisted men needed to continue the upkeep . By January 1866 , no funds were available even to keep Alexander ' s offices open , and on January 13 , 1866 , he declared , " . . . I closed up my office here , as far as it is possible to close it , before leaving . . . " . By July 14 , 1866 , all of the outstanding debts of the office of the defenses of Washington were paid off in full and its work was fully completed . California Years . As was common for many senior officers at the end of the war , Alexander was honored with a brevet rank of brigadier general in the regular army , effective March 13 , 1865 . Following his closure of the offices of the defenses of Washington , D . C . , he was briefly ordered to New England , where he supervised the renovation of various minor fortifications and river improvements in Maine . That posting came to an end on January 7 , 1867 , when he was ordered to the West Coast as the chief U . S . Army engineer in the region . He was promoted to lieutenant colonel on March 7 , 1867 . As chief engineer to the Military Division of the Pacific , he was the top U . S . Army Corps of Engineers officer on the entire American Pacific Coast . Upon his arrival on the West Coast , he visited locations from Alaska to the Mexican border in order to analyze the work that would be needed . Between 1868 and 1870 , he surveyed numerous California harbors and made engineering suggestions as required . One of these suggestions resulted in the construction of a 7 , 000 - foot breakwater that made Long Beach harbor accessible to large amounts of shipping for the first time . In 1870 , he suggested that landowners near Colusa , California , construct levees to contain the Sacramento River within a single channel . The plan would reclaim swampland and control the river ' s annual floods , making large - scale farming possible . The plan was eagerly seized upon by local residents . In the spring of 1872 , Col . Alexander and Maj . Gen . John M . Schofield , commander of the Military Division of the Pacific , sailed from San Francisco , California , to Honolulu in the then - independent Kingdom of Hawaii on a secret mission to evaluate Hawaii ' s ports in terms of defensive capabilities and commercial facilities . Fellow civil war veteran Alfred S . Hartwell was their host , who was on the kingdom ' s supreme court at the time . They recognized the great potential of Pearl Harbor as a " harbor of refuge in time of war , " and on May 8 , 1873 , recommended that the War Department acquire the harbor . Their suggestion resulted in the signing of the reciprocity Treaty of 1875 between the United States and Hawaii . As part of the treaty , Hawaii ceded the area of Pearl Harbor to the United States in return for trade agreements benefiting Hawaiian sugar planters . The treaty was signed on September 8 , 1876 , helping pave the way for eventual American annexation of the Kingdom . Irrigation and Land Reclamation . Following his return to California , Col . Alexander was appointed president of a board appointed by the U . S . Congress to study the potential of irrigating the San Joaquin Valley , Tulare Valley , and Sacramento Valley . The board , which became known as the Alexander Commission , conducted a survey of the California Central Valley throughout the summer and fall of 1873 . The Commission ' s report declared that large - scale irrigation was possible and that much land could be reclaimed from the swamps around the Sacramento River . The report was not initially acted upon , but was the first professional survey of the valley and set the stage for further development . In 1874 and 1875 , Alexander was assigned to a board examining the problem of keeping the Mississippi River Delta from silting up and becoming an impediment to ship traffic . During the course of his tenure on the board , he traveled to Europe in order to examine European solutions to the problem . At the end of 1875 , Alexander was asked by the state government of California to examine a proposed irrigation project in the San Joaquin Valley . Busy with other projects , Alexander appointed an associate , William Hammond Hall , to head the project . Alexander died in San Francisco , California , on December 15 , 1878 , at the age of 59 . He was buried in the San Francisco National Cemetery .