Gay and lesbian New Yorkers will be allowed to marry for the first time on Sunday. Long queues are expected outside registry offices across the city.
A law passed last month in Albany made New York the seventh state to allow gay marriage.
The proposal to allow same sex couples to marry was put forward by state governor David Patterson. It passed very narrowly.
A recent report suggested the change in the law could add an extra $US400 million to the state's economy over the next three years.
Gay marriage was legal in California for a while but was banned again last year.
The BBC reports 823 couples entered a lottery in New York for the chance to get married on Sunday.
Initially it was thought that numbers would be limited to 764, but it was announced on Thursday that everyone who registered by the deadline will have the chance to marry.