Diane, a nurse from Houston, Texas, sunbathes at the beach next to her husband, both wearing facemasks, in Miami Beach, Florida on June 16, 2020.

The U.S. headed into the Fourth of July weekend with many parades and fireworks displays canceled, beaches and bars closed, and health authorities warning that this will be a crucial test of Americans' self-control that could determine the trajectory of the surging coronavirus outbreak.

With confirmed cases climbing in 40 states, governors have ordered the wearing of masks in public, and families were urged to celebrate their independence at home. Even then, they were told to keep their backyard cookouts small.