The Spanish-American War, fought in 1898, was a significant conflict that marked the emergence of the United States as a global power. During this conflict, the 4th Corps played a crucial role as part of the American military's organizational structure. The 1st Division within the 4th Corps was tasked with various responsibilities, including engagements in key theaters of the war.
 
The 4th Corps, commanded by General Joseph Wheeler, played a vital role in the Cuban campaign, which was a major theater of operations during the war. The 1st Division, led by Brigadier General Joseph Lawton, was composed of a mix of volunteer and regular army units. These divisions were involved in intense fighting, most notably during the Battle of El Caney and the Siege of Santiago de Cuba.
 
The 1st Division of the 4th Corps demonstrated resilience and bravery during these engagements. Their efforts contributed significantly to the overall success of the American forces in securing victory over the Spanish. The Spanish-American War resulted in the United States acquiring territories such as Puerto Rico, Guam, and the Philippines, marking a transformative period in American history and setting the stage for its increased involvement in global affairs.