William Cost Johnson was an American

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 politician.

Johnson was born near Jefferson, Maryland

Jefferson, Maryland

Jefferson is an unincorporated community located in Frederick County, Maryland, established in 1774, incorporated as a town in 1831. However, a year later, in 1832, the citizens of the town decided that municipal government was unnecessary, thus, it was disincorporated.- History of Jefferson...

, and studied law. He was admitted to the bar in 1831 and commenced practice in Jefferson. Johnson served as a member of the Maryland House of Delegates

Maryland House of Delegates

The Maryland House of Delegates is the lower house of the General Assembly, the state legislature of the U.S. state of Maryland, and is composed of 141 Delegates elected from 47 districts. The House chamber is located in the state capitol building on State Circle in Annapolis...

 in 1831 and 1832, and was elected as an Anti-Jacksonian to the Twenty-third Congress, serving from March 4, 1833 to March 3, 1835. He was also a delegate to the State constitutional convention in 1836.

Johnson was elected as a Whig to the Twenty-fifth, Twenty-sixth, and Twenty-seventh Congresses, serving from March 4, 1837 to March 3, 1843. In Congress, he served as chairman of the Committee on the District of Columbia (Twenty-sixth Congress), and as a member of the Committee on Public Lands (Twenty-seventh Congress). After Congress, he continued the practice of his profession until his death in Washington, D.C.

Washington, D.C.

Washington, D.C., formally the District of Columbia and commonly referred to as Washington, "the District", or simply D.C., is the capital of the United States. On July 16, 1790, the United States Congress approved the creation of a permanent national capital as permitted by the U.S. Constitution....

. He is interred in the Reformed Church Cemetery in Jefferson.