As America tentatively emerges from weeks of lockdowns, it is becoming clear that the pandemic has taken its toll on workers who have been on the front lines all along. They have packed and delivered supplies, cared for the sick and elderly, kept streets and buildings clean and taken other workers to their jobs. Thousands of them have gotten sick, recovered and returned to work. Many have died. An Associated Press analysis of census data shows that the burden of keeping the country open has been borne unevenly across gender, racial and socioeconomic lines. They are mostly women, they are mostly people of color and they are more likely than other workers to be immigrants.