The devastating Confederate defeats at Fort Donelson and Shiloh early in 1862 paved the way for the Federal occupation of railroad towns including Jackson, Trenton, Henderson, and Grand Junction. Confederate troops evacuated Jackson on June 7, and that afternoon two regiments under Union Gen. John McClernand marched in and seized the railroad depots and the telegraph office. The next afternoon, Union Gen John A. Logan arrived with four regiments that soon were camped all around Jackson. Union Gen. Jeremiah C. Sullivan later took command. The town remained under Union control until June 1863, when Gen. Ulysses S. Grant needed the troops for his advance on Vicksburg. Late in 1862, Confederate Gen. Braxton Bragg ordered Gen. Nathan Bedford Forrest to sever Grant's West Tennessee supply line. Forrest led his cavalry brigade to destroy tracks and bridges, December 15, 1862 - January 3, 1863. He and his men crossed the Tennessee River, defeated Union cavalry at Lexington, captured Trenton and Union City, and advanced into Kentucky. Sullivan reinforced Jackson and ordered that "the Negros in town will... be pressed into the service, and be employed in carrying stores within the inner line." On Christmas Day, Forrest led his brigade back into Tennessee. To stop him, Sullivan sent Federal brigades in pursuit. They caught up with Forrest at Parker's Crossroads on December 31 but he narrowly avoided defeat and led his men across the river to safety. Parker's Crossroads battlefield is at Exit 108.