Final answer:
The Buffalo Soldiers, African-American military units, served in the 10th Cavalry Regiment and the 24th and 25th Infantry Regiments, among others, and contributed significantly in various conflicts, despite facing racial discrimination.
Step-by-step explanation:
The African-American soldiers, known as Buffalo Soldiers, served primarily in segregated units within the U.S. Army and were active in several conflicts including the Indian Wars, the Spanish-American War, the Philippine-American War, and both World Wars. Among the most recognized units were the 10th Cavalry Regiment and the 24th and 25th Infantry Regiments. These regiments played significant roles in the American military, from assisting settlers and fighting in the Indian Wars to serving as park rangers and engaging in military conflicts abroad.
During the Spanish-American War, African-American soldiers also served in volunteer regiments like the so-called "Immunes," due to their perceived resistance to tropical diseases. Despite facing segregation and discriminatory treatment, these soldiers earned numerous accolades for their service. The Buffalo Soldiers widely distinguished themselves and are an essential part of U.S. military history, reflecting the complicated narrative of African-American military service and racial discrimination within the armed forces.