With encouragement from the state government and labor 's founding of the Congress of Industrial Organizations ( CIO ) , Philadelphia became a union city . Many trade unions discriminated against African Americans for years , and they were closed out of some labor advances . Workers ' dissatisfaction with conditions led to numerous strikes in the textile unions , and the CIO organized labor in other industries , with more strikes taking place . During the 1930s , the Democratic Party began to grow in Philadelphia , influenced by the leadership of the Roosevelt administration during the Depression . A newly organized Independent Democratic Committee reached out to residents . In 1936 , the Democratic National Convention was held in Philadelphia . The majority of voters in the city reelected the Democrat Franklin D. Roosevelt as president ; they also voted for Democratic Congressmen and state representatives . City government continued to be dominated by Republicans , but the politicians were elected by small margins
Democratic National Convention
1936 Democratic National Convention
History of Philadelphia