 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..