NEW YORK — Today is Independence Day, a federal holiday commemorating the approval of the Declaration of Independence by the Second Continental Congress on July 4, 1776, marking the United States of America as its own nation. The holiday is celebrated with parades, fireworks, BBQs, picnics and carnivals, and an easy and fun way to express national pride is to wear patriotic jewelry featuring an American flag design. This trend became common during World War I and World War II, and jewelry in the form of the American flag has been a popular niche in fine and costume jewelry ever since.