Complex sentence: In the 1950s, 15.9 percent of blacks were unemployed, but only 6 percent of whites were unemployed; this was partially due to the union seniority system of the factories.
Split into simpler sentences: In the 1950s, 15.9 percent of blacks were unemployed, but only 6 percent of whites were unemployed. This was partially due to the union seniority system of the factories.