Biohazard Cleanup Near West Millbourne Millbourne, PA

Millbourne is a borough in Delaware County, Pennsylvania, that borders Philadelphia along Cobbs Creek.

At just 0.073 square miles, Millbourne is the smallest municipality in Delaware County by area.

With 1,212 residents at the 2020 census packed into that tiny area, Millbourne is the most densely populated municipality in Pennsylvania, at more than 16,000 people per square mile.

Millbourne was first settled in 1682 by Samuel Sellers, an immigrant from Derbyshire, England, who bought land from William Penn and is credited with establishing the first twisting-mill in America.

The borough is named for Millbourne Mills, the Sellers family's flour mills on Cobbs Creek, which at their height produced about 250 barrels of Millbourne-branded flour a day.

Developers Samuel Shoemaker and John L. Fry built Millbourne's rows of semi-detached homes in 1907 and 1908, and the community split from Upper Darby Township to incorporate as a borough on October 12, 1909.

Millbourne is small enough that the entire borough is within walking distance of its own SEPTA station, Millbourne Station on the Market–Frankford Line, which opened in 1907 and offers about a 15-minute ride to Center City Philadelphia.

Millbourne Mills closed in 1926 and was replaced by a Sears, Roebuck & Co. store; when Sears moved away in 1988 the borough slid toward bankruptcy and was designated a financially distressed municipality in 1993, a status it finally shed in 2014.

In 2009 Millbourne adopted a land value tax — taxing the land itself rather than the buildings on it — an unusual move that helped the tiny borough stay solvent.

Millbourne has the most concentrated South Asian population of any place in the entire United States and is known as a "Little India"; after 9/11, many Sikh cab drivers relocated there from New York.