Why has the integration of women into Congress been so slow? Is there a "political glass ceiling" for women? Although women use the same strategic calculations as men to decide when to run, the decision regarding where to run is something else. While redistricting has increasingly protected incumbents, it also has the unintended consequence of shaping the opportunities for female candidates. The political geography and socio-economic profile of districts that elect women differ substantially from districts that elect men. With data on over 10,000 elections and 30,000 candidates from 1916...