This dissertation studies the interaction of immigration and fiscal policy. Chapter 1 establishes patterns of fertility, education, earnings for both immigrants and their children. Chapter 2 studies the substitutability of similarly qualified immigrants, as measured by educational attainment and degree field, and natives in production. I find a much greater degree of imperfect substitutability than previous literature and as a result can show the effects of previous immigration on the wages of unskilled workers is close to 0. Chapter 3 incorporates the findings from chapters 1 and 2 into a calibrated general equilibrium model with which I can run a number of immigration policy experiments. Using this framework I show that omitting the correlation between the skills of parents and their children will likely understate the effects of any immigration policy change in the U.S.