The group-centered theory of party development provides a new theoretical framework for understanding early party development. Specifically, it provides a logical framework to understand why early state legislators were motivated to engage in partisan gerrymandering during a period without national organizations. I use Pennsylvania as a case study to determine if partisanship influenced the creation of congressional district maps in 1802, 1812, and 1822. Using county-level congressional election returns and state legislative journals, I provide evidence of strategic partisan gerrymandering by the Democratic-Republicans during each apportionment year. I also show that the Federalist minority in Pennsylvania knew the national political impact of the process and attempted to influence congressional maps for their own partisan advantage. Lastly, I demonstrate how multi-member districts were the Democratic-Republicans’ weapon of choice to engage in partisan gerrymandering throughout the period. These results highlight the connection between state legislatures and congressional party politics during the first party era.