In December 1864, the unit took part in a successful raid led by Benjamin Grierson during which the Battle of Egypt Station and other actions were fought.

When President Abraham Lincoln issued the Emancipation Proclamation on 1 January 1863, he also called for four regiments to be raised from African-Americans.

At first there was a stigma attached to white officers in the colored regiments, but this was quickly overcome by the prospect of rapid promotion.

[4] When Osband was presented with a list of five corporals and 15 privates from the 4th Illinois Cavalry to be commissioned as officers in the new regiment, he refused to accept it.

Instead, he petitioned Brigadier General Lorenzo Thomas,[5] who was in charge of organizing the colored regiments,[6] to consider his own list of candidates.

[9] From its formation until January 1864, the 1st Mississippi Cavalry (African Descent) was attached to the post of Goodrich Landing, District of Northeast Louisiana.

The expedition entered Yazoo River and stopped at Haynes Bluff to pick up a detachment of 11 officers and 25 men from the 1st Mississippi (AD).

On 3 February, the expedition was fired on by artillery at Liverpool Heights, so troops were landed and skirmished with Brigadier General Lawrence Sullivan Ross' 500-man Texas cavalry brigade.

Coates decided to report these activities to his superior at Vicksburg, so Sergeants Isaac Trendall and Washington Vincent of the 1st Mississippi Cavalry (AD) were selected to carry the message 60 mi (97 km) overland through Confederate-controlled territory.

Coates' expedition occupied Yazoo City on 9 February 1864 where they were joined by five companies of the 1st Mississippi Cavalry (AD) which marched overland.

By this time Ross' brigade returned to the area and routed a patrol of 43 troopers of the 1st Mississippi Cavalry (AD), inflicting 18 casualties.

Ross was soon joined by 550 men from Brigadier General Robert V. Richardson's Tennessee brigade and the combined force attacked in the Battle of Yazoo City on 5 March.

On 11 July, the expedition set out from the Big Black River and marched to Port Gibson and ultimately Grand Gulf.

Osband ordered Cook and 330 troopers to march north from Vicksburg and destroy Confederate supplies in the area between the Mississippi and Yazoo Rivers.

On 22 September, Cook's men chased 150 Confederate horsemen 15 mi (24 km) to the Sunflower River and burned the plantation where they were camped.

[16] On 29 September 1864, Osband led 1,000 men from the 3rd USCC and three white cavalry regiments down the Mississippi River by boat to Bruinsburg where they disembarked.

Dana, Osband seized 13 hostages and 125 cattle which they turned over to the 48th and 50th United States Colored Infantry Regiments.

On 4 October, 1,200 cavalrymen from five cavalry regiments and two guns boarded steamboats at Natchez and went downstream to Tunica Bend where the force went ashore.

After seizing a few prisoners and some supply wagons, they were informed by a local black man that a Confederate force was camped at the McGehee plantation nearby.

[14] Only two Confederate partisans were killed, but Osband reported that the expedition took hostages and seized 50,000 board-feet of lumber, 20,000 bricks, 100 horses and mules, 300 sheep, and 50 cattle.

The 3rd USCC and the 2nd Wisconsin Cavalry Regiment crossed the Big Black and marched 15 mi (24 km) east in a feint.

At dark, the two regiments started campfires, but slipped back to the crossing point to rejoin the rest of the column.

Leaving the 5th United States Colored Heavy Artillery Regiment to guard the crossing, the expedition moved northeast through Benton and reached Vaughan's Station on 27 November.

After wrecking sections of the railroad, Osband's column moved west to Yazoo City on 29 November and southwest to Vicksburg on 4 December.

[9] On Dana's orders, Osband's brigade moved to Memphis, where it joined Brigadier General Benjamin Grierson's division.

Grierson's column reached Ripley, Mississippi, and Osband's brigade wrecked 0.5 mi (0.8 km) of railroad track and trestles south of Tupelo.

On 2 January near Franklin, Osband's brigade with the 3rd USCC in the lead, ran into a Confederate force under Brigadier General William Wirt Adams.

In snow and sleet storms, the column made it as far as Bastrop, Louisiana, before turning back to the Mississippi River, followed by 400 escaped slaves.

After the war ended the regiment undertook occupation duties and was assigned to the 1st Brigade, Cavalry Division, District of West Tennessee from June 1865 to January 1866.