The Battle of Gettysburg By Tej Patel?December 10, 2016; 2nd Hour. Before Gettysburg Abraham Lincoln?s famous line from his Gettysburg Address (Way Before the battle?.) Fredericksburg?the Union forces were slaughtered by the Confederates. Vicksburg?was, at the time, under siege by the Union in order to control the Mississippi and split the Confederates in half (a.k.a., the Anaconda Plan). ^ Siege of Vicksburg. ^ Before the Battle?What happened? When Gen. Lee learned that Meade is in Pennsylvania blocking them from Washington D.C., he based his forces in Gettysburg. Meade?s forces (primarily Brigade General Buford, and Colonel Chamberlain. Before the Battle?What happened? Lee wanted to weaken the North?s will and want to fight the South.