Devastating Confederate defeats at Fort Donelson and Shiloh early in 1862 paved the way for Federal occupation of railroad towns including Jackson, Trenton, Henderson, and Grand Junction. Confederate troops evacuated Jackson on June 7, and that afternoon Federal forces marched in. Gen. Jeremiah C. Sullivan soon took command of the occupation, which lasted until June 1863. Late in 1862, Confederate Gen. Braxton Bragg ordered Gen. Nathan Bedford Forrest to sever Gen. Ulysses S. Grant's West Tennessee supply line. Forrest led his cavalry brigade to destroy tracks and bridges from December 15, 1862, to January 3, 1863. He and his men crossed the Tennessee River, defeated Union cavalry at Lexington, and clashed with Sullivan's men at Salem Cemetery on Jackson's outskirts on December 19. After advancing into Kentucky, Forrest led his brigade back into Tennessee, where he narrowly avoided defeat at Parker's Crossroads on December 31 and escaped. Grand Junction, 50 miles south of Jackson on the Mississippi border, was a vital rail crossroads, and there late in 1862 Grant established his first camp for contrabands, escaped slaves seeking safety by the hundreds within Federal lines. Grant later wrote that what began at Grand Junction were the first steps in West Tennessee toward full-scale emancipation and foreshadowed Reconstruction. Many of the male contrabands soon joined the U.S. Colored Troops after the Emancipation Proclamation, which authorized the enlistment of black soldiers, was issued on January 1, 1863.