Following a request from Grant for assistance against Vicksburg, Banks finally laid siege to Port Hudson in May 1863. Two attempts to storm the works, as with Grant at Vicksburg, were dismal failures. The first, made against the entrenched enemy on May 27, failed because of inadequate reconnaissance and because Banks failed to ensure the attacks along the line were coordinated. After a bloody repulse, Banks continued the siege, and launched a second assault on June 14. It was also badly coordinated, and the repulse was equally bloody: each of the two attacks resulted in more than 1,800 Union casualties. The Confederate garrison under General Franklin Gardner surrendered on July 9, 1863, after receiving word that Vicksburg had fallen. This brought the entire Mississippi River under Union control. The siege of Port Hudson was the first time that African-American soldiers were used in a major Civil War battle. The United States Colored Troops were authorized in 1863 and recruiting and training had to be conducted.