In 1787, the US defined the Northwest Territory which included the area of present-day Indiana. In 1800, Congress separated Ohio from the Northwest Territory, designating the rest of the land as the Indiana Territory. President Thomas Jefferson chose William Henry Harrison as the governor of the territory, and Vincennes was established as the capital. After the Michigan Territory was separated and the Illinois Territory was formed, Indiana was reduced to its current size and geography. By December 1816 the Indiana Territory was admitted to the Union as a state.