Using a new migration data set, I document the U.S. internal migration between the periods 1960-2000. I find that the recent decline in migration is driven by lower migration across states, while within state migration has increased during the observed periods. Using a gravity framework, I estimate the effect of the state borders in the United States. I find that the border effect is strongly significant, and within state migration is 3.2 times higher than across state migration. Furthermore, the border effect has increased from 2.7 in 1960 to 3.6 in 2000. By using spatial and temporal variations, I find that the border effect is smaller in areas with similar social and economic characteristics, and the increase in the border effect can be attributed to the rising differences in house prices as states implement more restrictive land use regulations. I show that for high income destinations, the rise in regulations can explain all of the increase in the border effect.