The main issue was Cuban independence. Revolts had been occurring for some years in Cuba against Spanish colonial rule. The U.S. backed these revolts upon entering the Spanish–American War. There had been war scares before, as in the "Virginius" Affair in 1873. But in the late 1890s, American public opinion swayed in support of the rebellion due to reports of concentration camps (death estimates range from 150,000 to 400,000 people) set up to control the populace. Yellow journalism exaggerated the atrocities to further increase public fervor, and to sell more papers.