New Delhi, Nov. 27 -- Tucked in a narrow alley off Drury Street in Philadelphia's Center City, McGillin's Old Ale House takes you back in time, courtesy its oak floors, tin ceilings and walls lined with vintage signs. Along with the clink of pint glasses and laughter, another sound lingers: the echo of love stories.

Founded in 1860 by Irish immigrants William and Catherine McGillin, the tavern holds the distinction of being Philadelphia's oldest continuously operating pub. It has survived wars, recessions, Prohibition, and two pandemics. Yet its most surprising legacy is not its endurance, but the hundreds of romances that have unfolded under its roof.

For Irene Levy Baker, author of Love Letters to McGillin's, launched this month, the ...