Formation of the department
A department for domestic concern was first considered by the 1st United States Congress in 1789, but those duties were placed in the Department of State. The idea of a separate domestic department continued to percolate for a half-century and was supported by Presidents from James Madison to James Polk. The 1846–48 Mexican–American War gave the proposal new steam as the responsibilities of the federal government grew. Polk's Secretary of the Treasury, Robert J. Walker, became a vocal champion of creating the new department.
In 1849, Walker stated in his annual report that several federal offices were placed in departments with which they had little to do. He noted that the General Land Office had little to do with the Treasury and also highlighted the Indian Affairs office, part of the Department of War, and the Patent Office, part of the Department of State. Walker argued that these and other bureaus should be brought together in a new Department of the Interior. A bill authorizing its creation of the Department passed the House of Representatives on February 15, 1849, and spent just over two weeks in the Senate. The Department was established on March 3, 1849 (9 395), the eve of President Zachary Taylor's inauguration, when the Senate voted 31 to 25 to create the Department. Its passage was delayed by Democrats in Congress who were reluctant to create more patronage posts for the incoming Whig administration to fill. The first Secretary of the Interior was Thomas Ewing.
Early and later years of the department
Many of the domestic concerns the Department originally dealt with were gradually transferred to other Departments. Other agencies became separate Departments, such as the Bureau of Agriculture, which later became the Department of Agriculture. However, land and natural resource management, American Indian affairs, wildlife conservation, and territorial affairs remain the responsibilities of the Department of the Interior.
As of mid-2004, the Department managed 507 million acres (2,050,000 km²) of surface land, or about one-fifth of the land in the United States. It manages 476 dams and 348 reservoirs through the Bureau of Reclamation, 410 national parks, monuments, seashore sites, etc. through the National Park Service, and 544 national wildlife refuges through the Fish and Wildlife Service. Energy projects on federally managed lands and offshore areas supply about 28% of the nation's energy production.