Military and Congress

In the summer of 1861, Garfield was commissioned a lieutenant colonel in the Union Army. Later that year, he was promoted to the rank of brigadier general, commanding a brigade at the Battle of Shiloh in 1862.

Garfield's political career continued during wartime. In October 1862, he won a seat in Congress, representing Ohio's 19th Congressional District. After the election, Garfield relocated to Washington, where he developed a close alliance with Treasury Secretary Salmon P. Chase. Garfield became a member of the Radical Republicans, led by Chase, and found himself frustrated by moderates including Abraham Lincoln.

Garfield not only favored abolition, but also believed that the leaders of the rebellion had forfeited their constitutional rights. He supported the confiscation of southern plantations and the punishment of rebellion leaders.

Following President Lincoln's assassination, Garfield attempted to ameliorate the strife between his own Radical Republicans and the new president, Andrew Johnson. When Johnson undermined the Freedman's Bureau, however, Garfield rejoined the Radicals, subsequently supporting Johnson's impeachment.

Source: Biography.com