During his inauguration on 21 January 2013, President Obama became the first sitting president to make a plea for marriage equality for gay and lesbian men and women:
"It is now our generation’s task to carry on what those pioneers began. For our journey is not complete until our wives, our mothers, and daughters can earn a living equal to their efforts. Our journey is not complete until our gay brothers and sisters are treated like anyone else under the law — for if we are truly created equal, then surely the love we commit to one another must be equal as well."
You can watch his full speech below: