The Battle of Vicksburg in July 1863 was an important Union victory that gave them control of the Mississippi River. General Ulysses S. Grant led the Union forces of around 75,000 men against General John C. Pemberton's outnumbered Confederate force of about 34,000 defending Vicksburg. Through strategies of bombarding the city and blocking incoming boats, Grant was able to lay siege to Vicksburg until the Confederates surrendered after over a month. This split the Confederacy in half and allowed the Union to dominate western trade and cut off vital ports in Mexico.