butler's plan was formulated on the afternoon of june 8, 1864, calling for 3 columns to cross the appomattox and advance from city point (now named hopewell, virginia) with 4,500 men. the first and second consisted of infantry from maj. gen. quincy a. gillmore's x corps and u.s. colored troops from brig. gen. edward w. hinks's 3rd division of xviii corps, which would attack the dimmock line east of the city. the third was 1,300 cavalrymen under brig. gen. august kautz, who would sweep around petersburg and strike it from the southeast. if any of these three forces made a breakthrough, it would be able to move into the rear of the defenders opposing the other two. butler originally designated hinks to command the operation, but gillmore insisted that he was the senior officer and butler later complained, "i was fool enough to yield to him."