These fireworks can be purchased by a person 18 or older between June 4 and July 4 and between Dec. 1 and Jan 1. Although there are monthlong purchase periods, the Delaware Office of the State Fire Marshal stressed that permitted types of fireworks may be used only on July 4, Dec. 31 and Jan 1.

As NYC celebrates its 400th birthday, this year's Independence Day show promises new effects, soaring shells, and a glowing tribute projected on the Brooklyn Bridge.