What was the approximate strength what 5 Armies the Army of the Potomac the Cumberland the Tennessee Northern Virginia and Tennessee?

The strength of all these armies varied at different times. The Army of the Potomac was probably the biggest army through most of the war, as the main Union Army in the east, it often had over 100,000 men. The Army of the Cumberland and the Army of the Tennessee were two of the Union armies from the western theater and often operated together and probably averaged somewhere around 50,000. The strongest the Army of Northern Virginia ever was came in the summer of 1862, just after Robert E. Lee took command and moved out for the Seven Days battles, when it numbered 85,000. Most of the time it numbered around 60,000, but there were only 35,000 on the field most of the day at Antietam, and the Yankees outnumbered it 3 to 1. The Army of Tennessee usually numbered 50-60,000. Both these armies of Confederates shrank drastically during the last year of the war, while the Yankees were able to maintain troop levels or increase strength.