I'm unsure if you're asking if this is true or false or not, but if you are, then this would be false
While Robert E. Lee did indeed participate in this battle, being in command of the confederste forces, Uylsses S. Grant would actually be somewhere else, laying siege to Vicksburg, which was in Mississippi, over 1000 miles away. The general commanding the army at Gettysburg was General George G. Meade