Who impeached President Andrew Johnson?

On February 24, 1868, the House Judiciary Committee, lead by Thaddeus Stevens (PA), presented a resolution to the House of Representatives calling for the impeachment of President Andrew Johnson. The House, dominated by Radical Republicans, voted 126-47 (17 absent) in favor of impeachment.

House Judiciary Committee
Thaddeus Stevens
George S. Boutwell
John A. Bingham
C. T. Hulburd
John F. Farnsworth
F. C. Beaman
H. E. Paine