A lot of people thought Nancy S. Grasmick would never retire. A couple of governors wished she would. But when Dr. Grasmick finally stepped down from her job as Maryland schools chief in 2011, she was not only the longest-serving state superintendent in the nation but also among the most consequential. She was hired to make the tough decisions necessary to move Maryland schools into a new era of accountability, and over more than two decades she did that and more. Dr. Grasmick may not be solely responsible for Maryland public schools’ perennial ranking as among the best in the nation, but it’s impossible to imagine them achieving that distinction without her.