Back from the wilds of Virginia, where he hunts black bears with a bow and arrow and squirrels with a shotgun, John Hawkins was sitting in the Walter E. Washington Convention Center, shaking in his work boots. The man who spent the past two decades in a log cabin was about to see a doctor the first time in 21 years. "I hate this," he said Wednesday afternoon, squirming in his chair. "I gotta get back to the mountains." But Hawkins fought the urge to flee, waiting nervously for his number to be called. The large-scale free clinic, the first of its kind in the District, was his best shot at free medical care. Although he lives only three hours outside Washington, he hadn't been inside the Capital Beltway for more than 20 years. A part-time carpenter, Hawkins doesn't have health insurance, like the other nearly 2,000 patients who converged on the convention center Wednesday. By 2 p.m., more than 700 people had been treated, and lines grew longer. The treatment was underwritten by 44,000 donors who contributed $300,000.