MORRISTOWN, N.J. — Cindy Dreeszen and her husband live in one of the wealthiest counties in the United States. They have steady jobs, his at a movie theater and hers at a government office. Together, they earn about $55,000 a year. But with a 17-month-old son, another baby on the way, and, as Ms. Dreeszen put it, “the cost of everything going up and up,” the couple went to a food pantry this month to ask for some free groceries. “I didn’t think we’d even be allowed to come here,” said Ms. Dreeszen, 41, glancing around at the shelves of...