Attendance at the National September 11 Memorial Museum is defying expectations, with 15,000 more visitors than projected since its May opening, which was marred by controversy.

More than 300,000 people have walked through the museum's doors since it opened on May 15, initially only to first responders, victims' families and survivors. That is about 5% more than originally expected, said museum spokesman Anthony Guido.

Most visitors are from New York State, he said. California has the second most visitors and New Jersey the third most.

"I wanted to see it," said Chelsea resident Bob Kaufman, 74, who brought his two young grandsons to the museum Wednesday afternoon. "Museums are tricky. They are hard to construct and keep tasteful as well as accurate. I think they did a superb job."

The museum, which was opened to the public on May 21, features first-person testimonials of both the 1993 and 2001 attacks, artifacts from the wreckage and other materials that are related to the events of 9/11 and its aftermath. Planning for the museum formally began in 2005.

The attendance is a positive development for the museum, which was heavily criticized for everything from its admission price to its gift shop items and cafe.

Many were vocal about their opposition to opening a museum above unidentified remains.

Some argued the admission price, $24 for adults, was too steep. Admission is free for victims' family members.

Kaufman, a longtime New Yorker who said he's been meaning to visit, wasn't bothered by gift shop.

"I took a quick look around," he said. "I didn't find it offensive. I understand why they have to have it."

But that isn't the case for everyone. San Francisco resident Chris Gebert said Wednesdayhe came to pay his respects to the many who lost their lives that day. And while he found the museum very respectful and informative, he said the gift shop was a little jarring.

"It's such a deep moving experience," said Gebert, 28. "And then all of a sudden there's a gift shop."

His friend, Marty Schwartz, 29, said he was surprised to see the items for sale.

"It's disrespectful to the families and the moment," Schwartz said.

Guido said it's too soon to say why so many more people are visiting than expected. The museum hopes to draw 2.5 million visitors in the first year, he said, a number based on demand levels and capacity levels.

Mayor Bill de Blasio said the "extraordinary" attendance does not surprise him and that he would work with federal authorities to try to lower ticket costs.

"It's one of the most important sites in the country and people clearly feel that," de Blasio said Wednesday at an unrelated event. "I certainly think we want to work with our federal partners to address the cost of the museum. I think there should be federal involvement that's something we'll keep working on."

The reasons people decided to visit varied, but most of them had one thing in common: no trip to New York City would be complete without it. And many who were not local to the area seemed unaware of it's controversial opening.

Carrie Hicks, visiting from Cleveland with her 12-year-old son, Adam, said a piece of one of the tower walls had been displayed at their local fire department. That piece is now apart of the museum.

"It was very emotional," Hicks said Wednesday. "I found it very respectful, very tastefully done."

(With Dan Rivoli)