Patapsco River, Baltimore
For most of its length it is a small, insignificant river, but in Baltimore the Patapsco River's tidal estuary forms the Inner Harbor. Outside of Baltimore the river had little historical significance except it served as the original route of the B&O Railroad. Of course, the most famous event to occur on the river was the War of 1812 battle where the British Navy shelled Fort McHenry, inspiring Francis Scott Key to write the Star Spangled Banner.
The river drains just 53 square miles, most of which is urban land. Patapsco Valley State Park extends along 32 miles of the Patapsco River, and it offers hiking, fishing, camping, canoeing, horseback and mountain bike trails, as well as picnicking pavilions. A variety of fish live in the river including smallmouth bass, rock bass, redbreast sunfish, hog suckers and white suckers.
The river also has some whitewater rafting, crabbing, and ice skating.
Patapsco River is the main river around Baltimore; it's easily accessed at Canton, where you can walk along it's shores. Unlike the Inner Harbor, the Patapsco River doesn't have a multitude of skyscrapers, seagulls, museums, or blue water; here the water is filled with trash and sewage, and the air hangs with a bad stench. The only nice thing about this area is that there are virtually no crowds. Looking across the river, you can make out Fort McHenry, which I will have to save for a later visit.