Question: What was the position in the United States Army of the Lieutenant general that Confederate General Robert E. Lee surrendered to?

Context:
Lee's Farewell Address
Confederate General Robert E. Lee issued his Farewell Address, also known as General Order No. 9 (sometimes Orders) to his Army of Northern Virginia on April 10, 1865, the day after he surrendered the army to Lt. Gen. Ulysses S. Grant.
 Lee's surrender was instrumental in bringing about the end of the American Civil War.
 The text of the order, which were written and drafted by Col. Charles Marshall, edited and finalized by Lee, were issued as follows:
Ulysses S. Grant
Ulysses S. Grant, born Hiram Ulysses Grant , (April 27, 1822 – July 23, 1885) was the Commanding General of the United States Army at the end of the American Civil War and later the 18th President of the United States from 1869 to 1877.
 As Commanding General, Grant worked closely with President Abraham Lincoln to lead the Union Army to victory over the Confederacy in the Civil War.
 Supported by Congress, Grant implemented Reconstruction, often at odds with President Andrew Johnson.
 Twice elected president, Grant led the Republicans in their effort to remove the vestiges of Confederate nationalism and slavery, protect African-American citizenship, and support economic prosperity.
 Although his presidency has often been criticized for multiple administration scandals and for his failure to alleviate the economic depression following the Panic of 1873, he is regarded as a President who performed relatively well in the context of his time and pursued justice for all.
Harris Farm Engagement
The Harris Farm Engagement was a military engagement between the Union Army and the Confederate States Army.
 The Harris Farm Engagement was a part of the Battle of Spotsylvania Courthouse.
 The battle was led by Union Major General Winfield S. Hancock and Confederate general Richard S. Ewell.
 The battle was caused when the Union commander, Lt. Gen. Ulysses S. Grant ordered Hancock's Union II Corps to trap Confederate soldiers between Richmond and Fredericksburg.
 Before General Hancock could trap the Confederate soldiers, Confederate General Robert E. Lee ordered Lieutenant General Richard S. Ewell, in command of the "Confederate "II Corps to ambush General Hancock's troops at the Harris Farm (also known as Bloomsbury Farm).
Appomattox Campaign
The Appomattox Campaign was a series of American Civil War battles fought March 29 – April 9, 1865 in Virginia that concluded with the surrender of Confederate General Robert E. Lee's Army of Northern Virginia to forces of the Union Army (Army of the Potomac, Army of the James and Army of the Shenandoah) under the overall command of Lieutenant General Ulysses S. Grant.
 In the following eleven weeks after Lee's surrender, the American Civil War ended as other Confederate armies surrendered and Confederate government leaders were captured or fled the country.
Isaac R. Trimble
Isaac Ridgeway Trimble (May 15, 1802 – January 2, 1888) was a United States Army officer, a civil engineer, a prominent railroad construction superintendent and executive, and a Confederate general in the American Civil War.
 He was born in Virginia, lived in Maryland for much of his adult life, and returned to Virginia in 1861 after Maryland did not secede.
 Trimble is most famous for his role as a division commander in the assault known as Pickett's Charge at the Battle of Gettysburg.
 He was wounded severely in the leg during that battle, and was left on the field.
 He spent most of the remainder of the war as a prisoner, and was finally paroled on April 16th, 1865, one week after Robert E. Lee surrendered the Army of Northern Virginia following the Battle of Appomattox Court House on April 9th.
Battle of Lewis's Farm
The Battle of Lewis's Farm (also known as Quaker Road, Military Road, or Gravelly Run) was fought on March 29, 1865, in Dinwiddie County, Virginia near the end of the American Civil War.
 In climactic battles at the end of the Richmond–Petersburg Campaign, usually referred to as the Siege of Petersburg, starting with Lewis's Farm, the Union Army commanded by Lieutenant General Ulysses S. Grant dislodged the Confederate Army of Northern Virginia commanded by General Robert E. Lee from defensive lines at Petersburg, Virginia and the Confederate capital of Richmond, Virginia.
 Many historians and the United States National Park Service consider the Battle of Lewis's Farm to be the opening battle of the Appomattox Campaign, which resulted in the surrender of Lee's army on April 9, 1865.
Third Battle of Petersburg
The Third Battle of Petersburg, also known as the Breakthrough at Petersburg or the Fall of Petersburg, was fought on April 2, 1865, south and southwest of Petersburg, Virginia, at the end of the 292-day Richmond–Petersburg Campaign (sometimes called the Siege of Petersburg) and in the beginning stage of the Appomattox Campaign near the conclusion of the American Civil War.
 The Union Army (Army of the Potomac, Army of the Shenandoah and Army of the James) under the overall command of General-in-chief, Lieutenant General Ulysses S. Grant, launched an assault on General Robert E. Lee's Confederate Army of Northern Virginia's Petersburg, Virginia trenches and fortifications after the Union victory at the Battle of Five Forks on April 1, 1865.
 As a result of that battle the Confederate right flank and rear were exposed, and the remaining supply lines cut, and the Confederate defenders were reduced by over 10,000 men killed, wounded, taken prisoner or in flight.
Lee Family Digital Archive
The Lee Family Digital Archive is a scholarly effort to collect, edit, and disseminate the papers of the Lee family of Virginia.
 The Lees of Virginia included Richard Lee I, the immigrant founder of the family, who came to Virginia from England around 1640, and his descendants.
 Some of the most famous Lees are Thomas Lee, the President of Virginia; Richard Henry Lee and Francis Lightfoot Lee, signers of the Declaration of Independence; Arthur Lee, the Penman of the Revolution; Light-Horse Harry Lee, the cavalry hero of the Continental army, three-time governor of Virginia, and the father of Robert E. Lee; Thomas Sim Lee, Revolutionary governor of Maryland; Richard Bland Lee, U.S. Senator; Charles Lee, U.S. Supreme Court justice; Richard Bland Lee II, a noted explorer; Robert E. Lee, the Confederate general who is by far the most famous of the family; William Henry Fitzhugh (Rooney) Lee, the son of Robert E. Lee and a U.S. Congressman from Virginia; and Fitzhugh Lee, Governor of Virginia and Civil War cavalry general.
 President Zachary Taylor was a Lee descendant, on his mother's side.
Battle of Appomattox Court House
The Battle of Appomattox Court House (Virginia, U.S.), fought on the morning of April 9th, 1865, was one of the last battles of the American Civil War (1861-1865).
 It was the final engagement of Confederate States Army general Robert E. Lee's Army of Northern Virginia before it surrendered to the Union Army / Army of the Potomac under Lt. Gen. and General-in-Chief Ulysses S. Grant.
 Lee, having abandoned the Confederate capital of Richmond, Virginia, after the ten-month Siege of Petersburg and Richmond, retreated west, hoping to join his army with the remaining Confederate forces in North Carolina of the Army of Tennessee under Gen. Joseph E. Johnston.
 Union infantry and cavalry forces under Gen. Phillip Sheridan pursued and cut off the Confederates' retreat at the central Virginia village of Appomattox Court House.
 Lee launched an last-ditch attack to break through the Union forces to his front, assuming the Union force consisted entirely of lightly armed cavalry.
 When he realized that the cavalry was now backed up by two corps of Federal infantry, he had no choice but to surrender with his further avenue of retreat and escape now cut off.
Battle of West Point
The Battle of West Point was fought on April 16, 1865 in West Point, Georgia, during General James H. Wilson's raid in the South during the American Civil War.
 This battle was fought at Fort Tyler seven days after Confederate General Robert E. Lee surrendered to Union General Ulysses S. Grant and two days after the assassination of President Abraham Lincoln, making it one of the last battles of the Civil War east of the Mississippi River and making Fort Tyler the last Confederate fort captured by the Union.
 The same day, just 30 miles to the south, the Battle of Columbus, Georgia, was fought by another division of Wilson's raiders.
 News of the surrender of Robert E. Lee's Army of Northern Virginia reached the opposing forces in Georgia the day after the battle effectively ending the war east of the Mississippi River.

Answer: Commanding General