Families spread lawn chairs across the field at Concord's North Bridge on the evening of Friday, July 24, as fife and drum players in period costume performed and a cannon blast lit up the summer sky to mark 250 years of American independence.

The celebration at Minute Man National Historical Park drew attendees of all ages to the site where Colonial Militia exchanged gunfire with British regulars on April 19, 1775, in what became known as the "shot heard 'round the world." On this night, the gunfire was ceremonial: a cannon firing in honor of the Declaration of Independence, followed by a full reading of the document itself.

The park invited the public to arrive at 8:30 p.m. for the program, which the park announced on Facebook as part of its broader America 250 summer programming. Some attendees came in 18th-century garb. Others wore jeans and sneakers. Mike Shook attended with his dog Obi.

Photos published by The Concord Bridge on Thursday, July 30, show the crowd settled into lawn chairs on the field overlooking the bridge, watching fifers and drummers perform as the evening darkened. Photographer Jon Chase captured the scene.

The evening was one in a series of America 250 events at local historic sites this summer. On July 4, a Declaration of Independence reading at the Lexington Visitors Center drew visitors from eight states and three countries. The North Bridge event brought the celebration to Concord's most storied ground.

The National Park Service has invested in restoring historic structures, monuments, and trails at Minute Man National Historical Park as part of its America 250 initiative, funded through the Great American Outdoors Act.

The bridge visitors cross today is the fifth to stand at the site since the original, which was taken down in 1788, according to the National Park Service. The current span dates to a 2005 restoration.

National Park Week runs Aug. 22-30, with a fee-free day on Aug. 25 marking the National Park Service's 110th birthday.