sentences:  A group of congressmen known as the Radical Republicans often became frustrated with Lincoln's conduct of the war and reluctance to immediately push abolition, but Lincoln was able to maintain good relations with many of the Radical Republican leaders, including Senator Charles Sumner.Congressional Democrats, on the other hand, tended to oppose Lincoln's policies regarding both the war and slavery.In January 1862, Lincoln, frustrated by months of inaction, ordered McClellan to begin the offensive by the end of February.