Final answer:
Eugene Debs became the leader of the left after Depretis's death in July 29th, 1887. He was a labor leader and a founding member of the Socialist Party of America.
Step-by-step explanation:
Eugene Debs became the leader of the left after Depretis's death in July 29th, 1887. Debs was a labor leader and a founding member of the Socialist Party of America (SPA). He advocated for change through the ballot box and ran for president as the SPA candidate in several elections. Debs played a significant role in leading the labor movement during the late 19th and early 20th centuries.