Find memorable shirts, hats, coins, mugs, and more to celebrate America's 250th birthday. (iStock) As America prepares to celebrate its 250th birthday, commemorative products are already hitting virtual store shelves. From 250th anniversary American flags and patriotic baseball caps to challenge coins minted by one of the country's oldest mints, these are some of the standout items worth checking out. READ MORE:  America 250 is coming: What to know and the best commemorative gear to buy 250th