In mid-February 1863, Confederate troops at Cypress Bend fired on Union transports on the Mississippi River. On Feb. 19, a force of Union cavalry and mule-mounted infantry set out in pursuit. The Union troops drove off enemy pickets before encountering Confederate artillery at Amos Bayou. The combatants traded fire until Union canister forced the Confederates back. The U.S. soldiers crossed the bayou on home-made rafts, but darkness halted their pursuit. The next day, they found a 12-pound howitzer the Confederates had to leave behind.