The extent to which legislators pursue their privately held preferences in office has important implications for representative democracy and is exceedingly difficult to measure. Many models of legislative decision-making tacitly assume that members are willing and able to carry out the wishes of their constituents so as to maximize their reelection prospects and, in so doing, relegate their personal preferences. This project explores this assumption by examining the role that members’ place of birth plays in shaping legislative behavior, apart from other politically relevant factors like partisanship. We find that birthplace exerts an independent influence on members’ voting behavior. Using a variety of geographic measures, we find that members who are born in close proximity to one another tend to exhibit similar patterns in roll call voting, even when accounting for partisanship, constituency attributes, and a variety of other determinants of voting. We also demonstrate in a secondary analysis that the agricultural composition of members’ birthplace influences their support for agricultural protection. Our findings suggest that members’ personal history shapes the representational relationship they have with their constituents.