As a part of that plan, the 1st Cavalry (Corps d'Afrique) was organized at New Orleans, Louisiana, and mustered in on September 12, 1863,[2] for three years' service.

Company H was composed of freedmen recruited by Captain Franz Beuter after the Union occupation of Indianola, Texas in late 1863 and early 1864.

On March 22, 1864, while accompanying a XIX Corps movement to Alexandria during the Red River campaign, Second Lieutenant William Hamblin, formerly of the 3rd Massachusetts Cavalry, was captured by Confederate guerrillas near Washington, Louisiana, north of Opelousas.

[6] Though unmounted and their weapons unloaded, the 4th led the procession, which included social, civic, religious, abolitionist and benevolent groups.

In the procession was the family of Captain Andre Cailloux, the Louisiana Native Guard officer who was killed in the Siege of Port Hudson.

[4] As the 4th was still being fully mounted, the regiment participated in an expedition to Clinton, Louisiana from August 23–29, 1864 to flush out Confederate jayhawkers based there.

While on that expedition, the regiment saw combat action on August 25 at Olive Branch, on the Comite River about ten miles south of Clinton, resulting in one soldier wounded.

Upon his medical discharge in November 1864 as a result of adverse effects of a gunshot wound, regiment commander Lieutenant Colonel Julius H. Alexander was replaced by Major Nathaniel C. Mitchell, formerly of the 15th Illinois Cavalry.

The 4th went on an expedition from Port Hudson to Jackson, Louisiana from April 11–13, 1865 to escort an engineering team repairing telegraph lines.

Using the repaired telegraph line, the 4th confirmed to the Confederate forces at Osyka that General Robert E. Lee had already surrendered the Army of Northern Virginia on April 9.