Complex sentence: He won two notable legal victories in defending workers against corporations--the first was in securing compensation for dependents of railroad workers who were killed in revolutionary battles, the second was to gain indemnities for miners injured at work.
Split into simpler sentences: He won two notable legal victories in defending workers against corporations. The first was in securing compensation for dependents of railroad workers who were killed in revolutionary battles; the second was to gain indemnities for miners injured at work.