The Case
In January of 1865 the US Congress passed a law that effectively debarred former members of the Confederate government by requiring a loyalty oath be recited by any Federal court officer affirming that the officer had never served in the Confederate government.
Augustus Hill Garland, an attorney and former Confederate Senator from Arkansas, had previously received a pardon from President Andrew Johnson. Garland came before the court and pleaded that the act of Congress was a bill of attainder and an ex post facto law which unfairly punished him for the crime he had been pardoned for and was therefore unconstitutional.