Complex sentence: From November 1862 to October 1864, when he was retired because of a wound received in the preceding August, he was colonel of the First South Carolina Volunteers, the first authorized regiment recruited from freedmen for Union military service.
Split into simpler sentences: From November 1862 to October 1864, when he was retired because of a wound received in the preceding August. He was colonel of the First South Carolina Volunteers, the first authorized regiment recruited from freedmen for Union military service.