This paper explores the effect of extra schooling, induced through compulsory schooling laws, on the likelihood of becoming politically involved in the United States and the United Kingdom. U.S. data come from the annual National Elections Studies and the November Current Population Surveys. U.K. data come from the British General Election Studies and the Eurobarometer Surveys. Results find that educational attainment relates to several measures of political interest and involvement in both countries. For voter turnout, there is a strong, robust relationship between education and voting for the United States, but not for the United Kingdom. This is largely due to differences in voting registration across education groups. Using information on validated voting, results find that misreporting of voter status cannot explain the estimates. Results suggest that the observed drop in voter turnout in the United States from 1964-2000 would have been 10.4-12.3 percentage points greater if high school attainment had stayed at 1964 rates, holding all else constant. However, when conditioning on registration, U.S. results approach U.K. findings. This may indicate that registration rules present a barrier to low-educated citizens' participation. (Contains 33 references.) (SM)