President Lyndon B. Johnson
- Untreated wastes flowing into the Potomac River cause bacterial contamination that forces the closing of the river for swimming from Three Sisters Island to Fort Washington. Low dissolved oxygen levels between Geisboro Point and Fort Foote endanger fish.
- Blue Plains wastewater treatment plant is completed, with a capacity of 130 million gallons per day (mgd) in the primary treatment facility. The plant will treat wastewater for Washington, D.C. residents.
- The Interstate Commission on the Potomac River Basin and the Potomac Valley Conservancy District are created to protect the Potomac River Watershed.
- Congress enacts the first Federal Water Pollution Control Act.
- Low dissolved oxygen 3levels kill thousands of fish during the summer. The Washington Post calls the Potomac River, "an open sewer."
- The levels of raw and partially treated sewage emptying into the Potomac River from Washington, D.C., are double what they had been in 1932.
- The Chesapeake Bay Bridge-Tunnel opens to carry traffic over and under 17.6 miles of water.
- The Water Quality Act of 1965 passes, establishing a Federal Water Pollution Control Agency and requiring water quality standards.
- President Lyndon B. Johnson labels the Potomac "a national disgrace," and sets cleanup goals for 1975.