Anthony Brown kicks off his campaign for governor in 2014 after serving seven years as Gov. O'Malley’s lieutenant governor. (Astrid Riecken/For The Washington Post)

Maryland Lt. Gov. Anthony G. Brown (D) launched his campaign for the state’s top elective office on Friday, telling several hundred supporters gathered in Prince George’s County that after more than six years as the state’s No. 2, he knows best how to continue building a better future for the Old Line State.

“Last year’s victories and wins don’t guarantee this year’s Super Bowl or World Series,” Brown said to applause. “The greatest challenge of our time, as a state and as a nation, as we recover from this recession, is to address the persistent gaps, and disparities, that exist in our communities and our economy.”

“Get ready,” Brown said, “to make Maryland better for more Marylanders.”

Brown, 51, has spent much of his time as deputy to Maryland Gov. Martin O’Malley (D) delving into weighty policy areas, including helping to oversee implementation of President Obama’s Affordable Care Act.

But he is seeking to accomplish what no running mate has done at the ballot box since Maryland created the position more than four decades ago: become the first lieutenant governor to ascend to the state’s top job.

On Friday — 18 months before the 2014 election — Brown showed he could be a formidable candidate. Dozens of elected leaders and scores of public employee union members dotted the crowd for a highly choreographed kickoff.

Brown took the stage to the wailing brass of a 50-piece marching band, and aides corralled supporters in front of a 20-foot-high backdrop of U.S. and Maryland flags.

The distance that Brown must still travel, however, was also evident. With the exception of U.S. Rep. Donna F. Edwards (D-Md.) and his wife, none of the union leaders or well-known figures in Maryland politics who attended Friday’s event spoke out that they were prepared to endorse Brown.

Senate President Thomas V. Mike Miller Jr. (D-Calvert) took the stage early in the event, saying a Maryland governor had come from Prince George’s County in each century since the state’s existence and “it would be . . . fine if we had a governor from Prince George’s in the 2000s.” But off-stage, Miller said it wasn’t the time to endorse Brown. “Obviously, he’s my favorite candidate, but we have to see who his running mate is, what his platform is going to be.”

Brown is expected to face Maryland Attorney General Douglas F. Gansler and others in the race for the Democratic nomination.

Opening his campaign, Brown dedicated considerable time to his life story, billing himself as the patriot in the race, the highest current elected politician to have served in Iraq, and a dedicated civil servant — a Harvard-educated lawyer who chose the military and public office over the possible riches of the private sector.