In 1789 Congress created three Executive Departments: Foreign Affairs (later in the same year renamed State), Treasury, and War. It also provided for an Attorney General and a Postmaster General. Domestic matters were apportioned by Congress among these departments. The idea of setting up a separate department to handle domestic matters was put forward on numerous occasions. It wasn't until March 3, 1849, the last day of the 30th Congress that a bill was passed to create the Department of the Interior to take charge of the Nation's internal affairs:
The Interior Department had a wide range of responsibilities entrusted to it: the construction of the national capital's water system, the colonization of freed slaves in Haiti, exploration of western wilderness, oversight of the District of Columbia jail, regulation of territorial governments, management of hospitals and universities, management of public parks, and the basic responsibilities for Indians, public lands, patents, and pensions. In one way or another all of these had to do with the internal development of the Nation or the welfare of its people.
Some significant dates:
1849 Creation of the Home Department consolidating the General Land Office (Department of the Treasury), the Patent Office (Department of State), the Indian Affairs Office (War Department) and the military pension offices (War and Navy Departments). Subsequently, Interior functions expand to include the census, regulation of territorial governments, exploration of the western wilderness, and management of the D.C. jail and water system.
1850-1857 Interior's Mexican Boundary Commission establishes the international boundary with Mexico.
1856-1873 Interior's Pacific Wagon Road Office improved the historic western emigrant routes.
1869 Interior began its geological survey of the western Territories with the Hayden expedition. The Bureau of Education is placed under Interior (later transferred to the Department of Health, Education and Welfare).
1872 Congress establishes Yellowstone as the first National Park.
1873 Congress transferred territorial oversight from the Secretary of State to the Secretary of the Interior.
1879 Creation of the U.S. Geological Survey.
1884 Interior's Bureau of Labor is established (becomes the Department of Labor in 1888).
1887-1889 The Interstate Commerce Commission is established in Interior. The Dawes Act authorizes allotments to Indians.
1902 The Bureau of Reclamation is established to construct dams and aqueducts in the west.
1903 President Theodore Roosevelt establishes the first National Wildlife Refuge at Pelican Island, Florida. The Census Bureau is transferred to the Department of Commerce.
1910 The Bureau of Mines is created to promote mine safety and minerals technology.
Stephen T. Mather, National Park Service's First Director.1916 President Wilson signed legislation creating The National Park Service.
1920 The Mineral Leasing Act establishes the government's right to rental payments and royalties on oil, gas, and minerals production.
1925 The Patent Office is transferred to the Department of Commerce.
1930 The Bureau of Pensions is transferred to the Veterans Administration.
1934 The Taylor Grazing Act is enacted to regulate economic uses of public lands. The first Migratory Bird Hunting Stamp is issued. The Indian Reorganization Act abolishes the allotment system established in 1887, forms tribal governments, and affirms the Secretary's trust responsibilities. Oversight of Alaska, Hawaii, the Virgin Islands, and Puerto Rico is transferred to Interior.
1935 The Bureau of Reclamation completes construction of Hoover Dam.
1940 The U.S. Fish and Wildlife Service is created from the Bureau of Fisheries and the Bureau of Biological Survey.
1946 Interior's General Land Office and Grazing Service are merged into the Bureau of Land Management.
1950-1951 Interior assumes jurisdiction over Guam, American Samoa, and the Trust Territory of the Pacific Islands.
1977 The is established to oversee state regulation of strip coal mining and repair of environmental damage.
1980 The Alaska National Interest Lands Conservation Act is enacted adding 47 million acres to the National Park System and 54 acres to the National Wildlife Refuge System.
1982 The Minerals Management Service (now known as the Bureau of Ocean Energy Management, Regulation, and Enforcement) is established to facilitate mineral revenue collection and manage the Outer Continental Shelf offshore lands.
1993 The President convened the Northwest Forest Plan Summit and released the "Forest Plan for a Sustainable Economy and Sustainable Environment."
1996 Interior science and technology functions are consolidated in the U.S. Geological Survey.
2001 Gale A. Norton is nominated the first woman to serve as Secretary of the Interior.
2010 Secretary Ken Salazar signs order 3302, renaming the Minerals Management Service as the Bureau of Ocean Energy Management, Regulation, and Enforcement.
(Link: https://www.doi.gov/whoweare/history/)