Former President George W. Bush makes surprise visit to Sept. 11 museum in New York City

In this photo taken on Sunday, Dec. 14, 2014 and provided by the National September 11 Memorial and Museum, former President George W. Bush, center, makes an unannounced visit to the National September 11 Memorial & Museum in New York. At right is National September 11 Memorial & Museum President Joe Daniels. (AP Photo/National September 11 Memorial & Museum, Jin Lee) (The Associated Press)

In this photo taken on Sunday, Dec. 14, 2014, and provided by the National September 11 Memorial and Museum, former President George W. Bush, left, views exhibits with National September 11 Memorial & Museum President Joe Daniels during an unannounced visit to the National September 11 Memorial & Museum in New York. (AP Photo/National September 11 Memorial & Museum, Jin Lee) (The Associated Press)

In this photo taken on Sunday, Dec. 14, 2014 and provided by the National September 11 Memorial and Museum, former President George W. Bush, center, makes an unannounced visit to the National September 11 Memorial & Museum in New York. At left is National September 11 Memorial & Museum President Joe Daniels, and at right is museum Director Alice Greenwald. (AP Photo/National September 11 Memorial & Museum, Jin Lee) (The Associated Press)

Former President George W. Bush made a surprise visit to the Sept. 11 museum in New York City over the weekend.

A museum spokesman says the man who was president at the time of the terrorist attacks arrived unannounced around 6 p.m. Sunday. He was greeted by museum President Joe Daniels and Director Alice Greenwald.

Spokesman Michael Frazier says Bush toured the museum and exhibit and "took the time to shake a lot of hands" from people who thanked him for his service.

The museum announced in September that it had gotten its millionth visitor in less than four months after opening to the public. Visitors have come from all 50 states and more than 130 countries.