On 25 February 1915 Sam was proclaimed president when his predecessor, Joseph Davilmar Théodore, was forced to resign, because he was unable to pay the militiamen, known as the "Cacos", who had helped him overthrow Zamor.

[citation needed] As Haiti's fifth president in five turbulent years, Sam was forced to contend with a revolt against his own regime, led by Dr. Rosalvo Bobo, who opposed the government's expanded commercial and strategic ties with the United States.

Fearing that he would share the same fate as his predecessors, Sam acted harshly against his political opponents, particularly the better-educated and wealthier mulatto population.

President Woodrow Wilson, who was wary about the turn of events in Haiti, and especially the possibility that Bobo would take power, ordered American troops to seize the capital.

Sam's chief of police, Charles Oscar Étienne, who cleaned out the jails by executing his political opponents, inspired the boogeymen Haitian carnival disguises known as "Chaloska".