On Aug. 28, Ulysses S. Grant takes early steps in his ascent to military fame, appointed commander of federal forces for the district of southeastern Missouri at Cairo, Ill., where the Ohio and Mississippi rivers converge.

Experienced military officers are in much demand on the Union side early on, and Grant will soon be drawing recognition for his ability to fight hard and win battles farther west. He will later drive Union victories at Vicksburg, Miss., and battlefields in Tennessee en route to winning command of the Union army and – years from now – forcing the Confederacy’s surrender in 1865.

This week also brings a startling, unauthorized move by a Union general that rocks President Abraham Lincoln’s government: Maj. Gen. John Fremont declares martial law in Missouri and orders the state’s slaves emancipated.

“All person who shall be taken with arms in their hands within these lines, shall be tried by Court Martial, and, if found guilty, will be shot,” Fremont proclaimed. The property “of those who take up arms against the United States … is declared to be confiscated … and their slaves, if any they have, are hereby declared free men.”

Fremont’s bold order – aimed at reining in a divided border state that hasn’t seceded – sets abolitionists rejoicing. But the proclamation oversteps the bounds of Lincoln’s new confiscation law, and Lincoln soon sends a special messenger to have Fremont revise the order.

Lincoln is still a few years from announcing his famed Emancipation Proclamation. For now, the president is wary of linking an anti-slavery stance to his war effort for fear of eroding support in slave states that haven’t seceded and might be pushed to the Confederate side. Ultimately, Fremont’s proclamation will be revoked altogether.