Question

what was one effect the battle of Gettysburg had on the south

Answer 1

The Battle had numerous consequences for the Confederacy. The most tangible being the severe casualties. Pickett's Charge led to over 50% casualties from the 13,000 that had charged, leaving approximately 6,000 of those 13,000 left able to fight. The Confederates suffered about 33% casualties over the course of the battle, incredibly significant considering their population was much, much lower, meaning the manpower pool could not replenish their losses.

The Battle also, as said above, finally made Lee seem mortal. The victory led to Lincoln's reelection (something Lee was hoping to avoid by pressuring the northern states with his advance), and stopped the British from explicitly supporting the CSA. It was important, to be sure, but at the time, it seemed like just another battle. The war continued for two more years and casualties kept mounting, Lee kept leading his army to tactical victories, time and time again and he was still feared/respected by opposing generals.

I'd say the most important effect was the casualties and their effect became more pronounced as Lee's battles (almost always having high casualties) began to wear on the ability of the South to provide men and material.