The Louisiana Purchase, acquired from France during the presidency of Thomas Jefferson in 1803, added 875,000 square miles for 15 million dollars, about 3 cents per acre, and eventually numerous states emerged from it, including Missouri in 1821, doubling the size of the United States. The acquisition of the Platte Purchase Indian Territory in 1836 extended Missouri's boundary westward to the Missouri River. Meriwether Lewis and William Clark, Virginia natives, departed St. Louis in May 1804 on a voyage of discovery using canoes and oar-powered keelboats; Congress appropriated 2,500 dollars for the 8,000-mile round trip, which took two-and-a-half years and involved more than 40 men, the Indian interpreter Sacagawea, and a dog. Settlers crossed the Nodaway River inland at the rapids by way of Old Trail Road, a gateway to Holt County that became a feeder line for the Oregon Trail. Holt County was established in 1841, with Oregon, said to be named for an Indian princess, chosen as the county seat. Among the first pioneers, Jesse Carroll immediately built the first courthouse, jail, and the Carroll-Lenz Stagecoach Inn in the 1840s, assisted by his devoted black slave. In the mid-1800s, others traveled through Oregon, Missouri, down Sterrett Hill, crossed the Missouri River at Iowa Point, and continued westward to the California Gold Rush and the Pacific Northwest.