Question: What battle took place east of the second-largest drainage system on the North American continent?

full_context: Document 1: Mackenzie River: The Mackenzie River (Slavey language: Deh-Cho [tèh tʃʰò], "big river" or Inuvialuktun: Kuukpak [kuːkpɑk], "great river") is the largest and longest river system in Canada, and is exceeded only by the Mississippi River system in North America. It flows through a vast, isolated region of forest and tundra entirely within the country's Northwest Territories, although its many tributaries reach into four other Canadian provinces and territories. The river's mainstem runs 1738 km in a northerly direction to the Arctic Ocean, draining a vast area nearly the size of Indonesia. It is the largest river flowing into the Arctic from North America, and with its tributaries is one of the longest rivers in the world.
Document 2: Mississippi River: The Mississippi River is the chief river of the second-largest drainage system on the North American continent, second only to the Hudson Bay drainage system. Flowing entirely in the United States (although its drainage basin reaches into Canada), it rises in northern Minnesota and meanders slowly southwards for 2320 mi to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains all or parts of 31 U.S. states and 2 Canadian provinces between the Rocky and Appalachian Mountains. The Mississippi ranks as the fourth-longest and fifteenth-largest river in the world by discharge. The river either borders or passes through the states of Minnesota, Wisconsin, Iowa, Illinois, Missouri, Kentucky, Tennessee, Arkansas, Mississippi, and Louisiana.
Document 3: Missouri River Valley: The Missouri River Valley outlines the journey of the Missouri River from its headwaters where the Madison, Jefferson and Gallatin Rivers flow together in Montana to its confluence with the Mississippi River in the State of Missouri. At 2300 mi long the valley drains one-sixth of the United States, and is the longest river valley on the North American continent. The valley in the Missouri River basin includes river bottoms and floodplains.
Document 4: Battle of Nashville: The Battle of Nashville was a two-day battle in the Franklin-Nashville Campaign that represented the end of large-scale fighting west of the coastal states in the American Civil War. It was fought at Nashville, Tennessee, on December 15–16, 1864, between the Confederate Army of Tennessee under Lieutenant General John Bell Hood and Federal forces under Major General George H. Thomas. In one of the largest victories achieved by the Union Army during the war, Thomas attacked and routed Hood's army, largely destroying it as an effective fighting force.
Document 5: Missouri River: The Missouri River is the longest river in North America. Rising in the Rocky Mountains of western Montana, the Missouri flows east and south for 2341 mi before entering the Mississippi River north of St. Louis, Missouri. The river takes drainage from a sparsely populated, semi-arid watershed of more than half a million square miles (1,300,000 km), which includes parts of ten U.S. states and two Canadian provinces. When combined with the lower Mississippi River, it forms the world's fourth longest river system.
Document 6: Saint John River (Bay of Fundy): The Saint John River (French: "Fleuve Saint-Jean" ; Maliseet: "Wolastoq"( )) is a river, approximately 418 mi long, located principally in the Canadian province of New Brunswick, but also in and arising from the province of Quebec and the U.S. state of Maine. It forms part of the Canada–United States border in two different places along its length. The river drains an area of approximately 55000 km2 , of which slightly more than half is located in New Brunswick. Along that portion of the Atlantic shoreline of North America that lies between the St. Lawrence River and the Mississippi River, the Saint John River is the second longest waterway; only the Susquehanna is longer. It has been nicknamed the "Rhine of North America" for its scenery. The river is regulated by hydro power dams located at Mactaquac, Beechwood, and Grand Falls, New Brunswick.
Document 7: Battle of Appomattox Station: The Battle of Appomattox Station was fought between a Union Army (Army of the Potomac, Army of the James, Army of the Shenandoah) cavalry division under the command of Brigadier General (Brevet Major General) George Armstrong Custer and Confederate Army of Northern Virginia artillery units commanded by Brigadier General Lindsay Walker with support from some dismounted cavalrymen, artillerymen armed with muskets and some stragglers on April 8, 1865, at Appomattox Station, Virginia during the Appomattox Campaign of the American Civil War.
Document 8: Cumberland River: The Cumberland River is a major waterway of the Southern United States. The 688 mi river drains almost 18000 mi2 of southern Kentucky and north-central Tennessee. The river flows generally west from a source in the Appalachian Mountains to its confluence with the Ohio River near Paducah, Kentucky, and the mouth of the Tennessee River. Major tributaries include the Obey, Caney Fork, Stones, and Red rivers.
Document 9: 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.
Document 10: Battle of Munford: The Battle of Munford took place in Munford, Alabama, on Sunday, April 23, 1865, during the raid through the state by 1,500 Union Army cavalrymen under General John T. Croxton, part of the force participating in Wilson's Raid. The Battle of Munford and a minor action at Hendersonville, North Carolina on the same day were the last battles of the American Civil War in the Eastern Theater of the American Civil War (east of the Mississippi River).
Document 11: Colorado River: The Colorado River is one of the principal rivers of the Southwestern United States and northern Mexico (the other being the Rio Grande). The 1450 mi river drains an expansive, arid watershed that encompasses parts of seven U.S. and two Mexican states. Starting in the central Rocky Mountains in the U.S., the river flows generally southwest across the Colorado Plateau and through the Grand Canyon before reaching Lake Mead on the Arizona–Nevada border, where it turns south toward the international border. After entering Mexico, the Colorado approaches the mostly dry Colorado River Delta at the tip of the Gulf of California between Baja California and Sonora.
Document 12: Battle of Shiloh: The Battle of Shiloh, also known as the Battle of Pittsburg Landing, was a major battle in the Western Theater of the American Civil War, fought April 6–7, 1862, in southwestern Tennessee. A Union force known as the Army of the Tennessee under Major General Ulysses S. Grant had moved via the Tennessee River deep into Tennessee and was encamped principally at Pittsburg Landing, Tennessee on the west bank of that river, where the Confederate Army of Mississippi, under General Albert Sidney Johnston and second-in-command P. G. T. Beauregard, launched a surprise attack on Grant's army from its base in Corinth, Mississippi. Johnston was mortally wounded during the fighting; Beauregard, who thus succeeded to command of the army, decided against pressing the attack late in the evening. Overnight Grant was reinforced by one of his own divisions stationed further north and was joined by three divisions from another Union army under Maj. Gen. Don Carlos Buell. This allowed them to launch an unexpected counterattack the next morning which completely reversed the Confederate gains of the previous day.
Document 13: Battle of Monocacy: The Battle of Monocacy (also known as Monocacy Junction) was fought on July 9, 1864, approximately 6 mi from Frederick, Maryland, as part of the Valley Campaigns of 1864 during the American Civil War. Confederate forces under Lt. Gen. Jubal A. Early defeated Union forces under Maj. Gen. Lew Wallace. The battle was part of Early's raid through the Shenandoah Valley and into Maryland in an attempt to divert Union forces away from Gen. Robert E. Lee's army under siege at Petersburg, Virginia. The battle was the northernmost Confederate victory of the war. While the Union troops retreated to Baltimore, Maryland, the Confederates continued toward Washington, D.C., but the battle at Monocacy delayed Early's march for a day, allowing time for Union reinforcements to arrive in the Union capital. The Confederates launched an attack on Washington on July 12 at the Battle of Fort Stevens, but were unsuccessful and retreated to Virginia.
Document 14: Columbia River: The Columbia River is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, Canada. It flows northwest and then south into the US state of Washington, then turns west to form most of the border between Washington and the state of Oregon before emptying into the Pacific Ocean. The river is 1243 mi long, and its largest tributary is the Snake River. Its drainage basin is roughly the size of France and extends into seven US states and a Canadian province. The fourth-largest river in the United States by volume, the Columbia has the greatest flow of any North American river entering the Pacific.
Document 15: Battle of Columbia: The Battle of Columbia was a series of military actions that took place November 24–29, 1864, in Maury County, Tennessee, as part of the Franklin-Nashville Campaign of the American Civil War. It concluded the movement of Lt. Gen. John Bell Hood's Confederate Army of Tennessee from the Tennessee River in northern Alabama to Columbia, Tennessee, and across the Duck River. A Union force under Maj. Gen. John M. Schofield skirmished with Hood's cavalry, commanded by Maj. Gen. Nathan Bedford Forrest, and fortified a defensive line south of Columbia, but soon withdrew north across the Duck River, abandoning the town. Hood's invasion of Tennessee continued as he attempted to intercept Schofield's retreating army at Spring Hill.
ground_truth: The Battle of Munford