The territorial powers of Congress deal with the purchase, sale and regulation of federally held lands. These powers are granted to Congress in Article IV, Section 3 of the United States Constitution. Congress' three main territorial powers include admitting new states, acquiring and disposing of property and making rules pertaining to the use of the property.

Defining Congress' Territory

The U.S. government owns almost one-third of the country's land. These federally held territories are found in all 50 states. Government-owned lands include national parks, forests and wildlife areas, military bases, federal buildings and Native American reservations. The U.S. also controls territories outside the borders of the 50 states. These territories include Puerto Rico, Guam, American Samoa and the Virgin Islands. While not part of the United States, the outlying U.S.-acquired lands are governed by Congress.

Admitting New States

The power to admit new states is given to Congress in the first clause of Article IV, Section 3. There are rules concerning how a state may be formed. A new state can't be formed inside the borders of an existing state. Existing states also can't join together to form a new state unless the state legislatures and Congress agree to the arrangement. Any newly admitted state has the same status as existing states. No one state is more important than any other state.

Purchasing and Disposing of Territory

The second clause in Article IV, Section 3 gives Congress the power to buy and sell land. For example, if a military base or federal building is no longer needed, it may be sold or leased. Congress has the power to purchase new territories from foreign governments. It can also purchase land inside the U.S. from states, companies or individuals. Congress is not allowed to seize land, however, without providing compensation to the owner. This protection against property seizure is provided in the Fifth Amendment to the Constitution.

Regulating Territory

The laws governing the use of federal land are made by Congress. States often handle the policing of federal land within the state. However, if a state law contradicts a federal law concerning the use of the land, the federal law takes precedence. In the case of Native American reservations, the policing is usually done by the tribe though the land is federally owned. Federal territories that do not fall within the borders of a state are wholly legislated by Congress, unless Congress sets up a territorial government.