What do the locations of cities like New York City Chicago Houston and Philadelphia have in common?

New York City is located at the mouth of the Hudson River, which meets the Atlantic Ocean in New York Harbor.

Chicago is located at the mouth of the Chicago River, which flows into Lake Michigan.

Houston is located on the San Jacinto River, which meets the Gulf of Mexico in Galveston Bay.

Philadelphia is located at the confluence of the Delaware and Schuylkill rivers, which meet the Delaware Bay.