Cady’s Alley, Naylor Court, Crispus Attucks Park, Blagden Alley: These are sites of Michelin-starred restaurants and new speakeasies as well as hotbed of residential construction.

After more than a century of efforts aimed at clearing them, alleys have survived in the District. But many of today’s incarnations are a far cry from the rat-infested dwellings where tuberculosis spread like wildfire.