| Term | Definition |
| tenement | apartment building found in many cities around the nation |
| suburbs | residential neighborhoods |
| urbanization | the growth of cities |
| immigrants | people from other countries coming to America to look for jobs |
| political machine | well organized political organization that controls election results by awarding jobs and other favors in exchange for votes |
| trust | a legal combonation of companies brought together to gain control of an industry and reduce competition |
| progressives | reformers who dominated the political landscape of the early 1900s |
| settlement houses | institutions that provided educational and social services to poor people |
| muckraker | a writer whose investigative articles or books attacked abuses such as child labor or corruption |
| social gospel movement | a movement emphasizing the application of Christian principles to social problems |
| direct primary | an election open to all votes within the party |
| initiative | allowed all citizens to introduce a bill into the legislative and required members to take a vote on it |
| referendum | established a procedure by which voters cast ballots for or against proposed laws |
| recall | gave citizens a chance to remove an elected official from office before the person's term ended |