A massive heat wave and political divisions didn't stop Americans from celebrating the 250th anniversary of the country's founding.Show Caption Hide Caption Extreme heat cancels some America 250 celebrations. See where.A scorching heat wave has led to several cancellations of America 250 celebrations as some governors have urged residents to limit their outdoor time.Fireworks burst above marbled monuments honoring America’s forefathers for roughly 40 minutes as sun-drenched and rain-soaked Americans watched. The past-midnight display sparkled above the National Mall and on screens across the United States, marking the final note of America’s 250th birthday celebrations. From New York to California, people poured into city plazas, backyard barbecues, beaches and local bars on the Fourth of July for the super-sized anniversary. A massive heat wave that brought stifling...