It’s a tradition as old as the nation itself — which is now 236, for those keeping track. Every July Fourth, Americans cap a day of picnics, parades and patriotism by gathering to celebrate Independence Day with a show of bangs and booms, “oohs” and “aaahs” in the evening sky. Wednesday night’s annual Gainesville American Legion fireworks show at Laurel Park, drew the usual large crowd of revelers who know that, on the Fourth of July, what goes up ... must blow up.