What was one main reason for General Lee's surrender?

The selection of superior Union forces as a main reason for General Lee's surrender is well-founded. Throughout the latter stages of the Civil War, the Union Army, particularly under General Ulysses S. Grant, had gained significant numerical and logistical advantages over the Confederate forces. This included not only larger troop numbers but also superior supply lines and industrial capabilities. Lee's Army of Northern Virginia, while still led by one of the most skilled generals of the time, was increasingly outnumbered and faced with the harsh realities of dwindling supplies, fewer reinforcements, and the larger, better-resourced Union forces consistently applying pressure through various military campaigns.

This strategic disadvantage ultimately made it difficult for Lee to mount an effective defense or counteroffensive, leading him to conclude that further resistance would be futile. Therefore, the overwhelming strength and coordination of Union forces played a pivotal role in compelling General Lee to surrender at Appomattox Court House in April 1865.