Yes. According to NYC Visit Babe Ruth hit his first home run in Yankee Stadium in the first game ever played there.

BTW, we have a great admiration for Curt Flood, who New York Times sports columnist Robert Lipsyte called "Baseball's Last Martyr." For those who don't know, in 1969 Flood refused to be traded to the Philadelphia Phillies. His reason? He wasn't a piece of property to be bought and sold against his wishes. He ultimately lost his 1972 case in the Supreme Court, and his career, but all baseball players since then have benefited from his stance. And the heavy price he paid.