Hundreds of thousands braved record heat in Washington for the annual July 4th concert and fireworks.

Fireworks lit the skies over hallowed battlefields from the War of 1812 and the American Civil War. Big fireworks shows were also held in Philadelphia -- the nation's first capital -- and for New York City.

Earlier Wednesday, President Barack Obama welcomed 25 active duty U.S. service members as new American citizens sworn in at the White House. Mr. Obama said "immigration makes America stronger." The 25 who took the oath of allegiance to their new home come from 17 different countries, including Mexico, Colombia, Nigeria and Russia. But it is a disappointing holiday this year for many Americans. More than 1 million people in the East are still without power after last Friday's vicious wind and rain storm. Millions also are sweltering through a brutal heat wave that has sent temperatures above 38 degrees Celsius (100 Fahrenheit) in some places.

The heat, drought and wildfires still burning in the West have moved authorities to cancel fireworks shows in cities and towns in 20 states.

This year's 4th of July celebration marks the 236th anniversary of the country's declaration of independence from Britain. Drafted by Thomas Jefferson in June 1776, the Declaration of Independence is America's most cherished symbol of freedom.

The Continental Congress formally approved the document weeks later, on July 4.