"As advocates for the truths we are compelled to uphold, we speak with equal intensity and urgency in opposition to your promoting a goal that so deeply conflicts with your faith, not to mention the best interests of our society," wrote O'Brien, who served as archbishop of the nation's first diocese from October 2007 to August 2011.
The governor was not persuaded. He held a news conference in July 2011 to announce that he would make same-sex marriage a priority in the 2012 legislative session. He wrote back to the archbishop that "when shortcomings in our laws bring about a result that is unjust, I have a public obligation to try to change that injustice."
The measure, with exemptions for religious organizations that choose not to marry gay couples, passed the House of Delegates in February in a close vote. O'Malley signed it in March. Opponents then gathered enough signatures to put the bill to a statewide vote, and it passed with 52 percent in favor.
In total, nine states and the District of Columbia have approved same-sex marriage. The other states are Connecticut, Iowa, Maine, Massachusetts, New Hampshire, New York, Vermont and Washington.
Meanwhile, the weddings continued throughout the day Tuesday. Clayton Zook, 28, and Wayne McKenzie, 30, married by the waters of the Chesapeake Bay at the Black Walnut Point Inn on Tilghman Island.
"We've been together for six and a half years, so this one day doesn't really change a whole lot as far as our feelings," said Zook, of Baltimore. "It does change a whole lot in how we are recognized, and we're certainly felt more as equal in the state of Maryland now."