Two years ago, only 150 students attended Holabird Elementary, then a K-5 school in the southeastern corner of this city. Competition from charters and from regular public schools in nearby Baltimore County had drained families from Holabird, a chronic underperformer. So when Andres A. Alonso, the chief executive officer of the Baltimore city…

Lots of districts like to think they have close-knit leadership teams. But few school leaders can say they've ironed their clothes together, which became a morning ritual for a group from San Francisco that spent a week at the Harvard Business School in Boston. Joined by similar teams from seven other large districts, they camped out in dorm-like…