The lobby of the Marriott Marquis, Washington D.C., which features a metal sculpture by Baltimore-based artist Rodney Carroll. Washington's first convention center hotel opens May 1.

The lobby of the Marriott Marquis, Washington D.C., which features a metal sculpture by Baltimore-based artist Rodney Carroll. Washington's first convention center hotel opens May 1. Jeffrey MacMillan/Capital Business

The Marriott Marquis in downtown Washington opened Thursday, putting an end to decades-long wrangling over land swaps and public funding for the convention center hotel.

Save for a few last-minute ­details — the front desk’s chandelier has yet to clear customs, and the 1,175 guest rooms are still waiting for bedside phone-charging stations — the $520 million hotel was ready for business.

About 100 people attended the noon opening for the Marriott Marquis Washington, D.C., an ­anticlimactic affair preceded by a flag-raising ceremony. At 12:01 p.m., the hotel’s first guest walked in, rolling a suitcase behind him.

“I’ve been looking forward to staying here,” said Dan Pitts, a national account manager for Freeman Co., which oversees meetings and trade shows.

Pitts, who arrived in town from Boston on Tuesday, had been rooming at the Renaissance hotel nearby.

“It looks very nice,” he said of the Marriott Marquis.

The hotel — the District’s largest, at 1.1 million square feet — has been more than 20 years in the making. Then-Mayor Marion Barry first proposed the project in 1990. Since then, a number of contentious debates have added to the drama surrounding the hotel’s financing, development and construction. The economy added another hurdle when private financing options dried up in the wake of the recession. The District ultimately provided $206 million in public funding, or 40 percent of the hotel’s final cost, and ground was broken in late 2010.

As part of its deal with the District, at least 51 percent of the hotel’s employees were required to be District residents. The Marquis currently has about 500 employees — a number executives expect to increase in the coming months. Of those, 63 percent live in the District.

“We have spent the last three or four months putting together” the hotel’s staff, said Daniel A. Nadeau, general manager of the hotel. “Marriott has been preparing for this hotel for over a decade.”

The 16-story building has 83 meeting rooms and four eateries, including a sports bar, a diner and a whiskey bar. A fifth, more upscale restaurant has yet to be announced.

Marriott International has expanded rapidly in recent years. The hotel company added 26,000 rooms around the world last year, and 210,000 more rooms are in the works. The hotel giant also got a local boost in October 2012, when it took over management responsibilities for the sprawling Gaylord National Resort and Convention Center across the Maryland line at National Harbor.

Hotel executives and city officials alike are hoping the Marquis will help woo new convention business to the District, which has been hit with widespread cancellations and shrinking group bookings in recent years. In 2012, citywide bookings accounted for 363,652 nightly hotel bookings, down from 480,892 in 2011, according to a March 26 disclosure by Events D.C.

But there may be signs of improvement. Marriott announced earlier this week that a resurgence in group travel in North America helped push up first-quarter profit by 26 percent. The District, which still lags behind much of the country, also seems to be improving.

“We haven’t seen group [bookings] pick up in a long time,” said Laura E. Paugh, senior vice president of investor relations for Marriott. “Even in D.C., where it’s been kind of rocky, things have stabilized a bit.”

Unlike the Marriott Marquis in New York City’s Times Square, which attracts a stream of vacationers, the Washington location will primarily serve business travelers.

The first crop of conference-

goers will arrive Saturday, when the American Society for Training and Development takes over 700 of the hotel’s rooms for its annual convention.

Capital Business is The Post’s regional publication focusing on the region’s business community. For more Washington business news, go to capbiz.biz.