This study examines the effect of same-sex marriage legalization on marriage rates from 2003 through 2015 when same-sex marriage became legal across all 50 states. Using a difference-in-differences approach, we compared marriage rates across the years before and after the legalization of same-sex marriage to identify any significant changes. Given their geographical proximity, cultural and political similarities, New York and New Jersey serve as ideal candidates for this analysis. Further, as a robustness check, this analysis is extended nationwide with the use of a two-way fixed-effect model. This research contributes to ongoing discussions about the evolving definition of marriage and its implications for societal norms. Ultimately, the effect of same-sex marriage legalization are small, but there is some evidence for a small increase in coupling.