In the Battle of Gettysburg, Union forces depended significantly on signal flags for efficient communication.

This visual system enabled commanders to transmit crucial messages rapidly across the battlefield, facilitating coordination among different units. Although horseback messengers were also employed, signal flags offered a more effective means of communication amid the chaos of war. The capacity to send messages quickly allowed the Union Army to stay organized and responsive during critical moments of the battle. Ultimately, the successful use of signal flags was instrumental in providing the Union with a strategic edge, contributing to their victory at Gettysburg.