After the United States acquired the Louisiana territory in 1803, President Thomas Jefferson dispatched Lewis and Clark to explore the north. Concurrently, Lieutenant Zebulon Pike and his soldiers embarked on a mission to investigate the territory’s southern boundary in 1806. Their task included tracing the Arkansas and Red Rivers and returning 51 Osage Indians to Kansas. Pike’s journey featured diplomatic efforts with Native tribes and an attempt to summit Pike’s Peak. Misjudgments led to confusion, eventually resulting in his capture by Spanish authorities in Santa Fe, Mexico. Pike’s expedition ended without achieving its goals. His account, published in 1810, garnered international attention. Although Pike’s exploration didn’t locate the Red River’s headwaters, his work enriched geographic knowledge and insights into regional societies.