The Cuyahoga River at one time was one of the most polluted rivers in the United States. The reach from Akron to Cleveland was devoid of fish. A Kent State University symposium, convened one year before the infamous 1969 fire, described one section of the river:

From 1,000 feet below Lower Harvard Bridge to Newburgh and South Shore Railroad Bridge,the surface is covered with the brown oily film observed upstream as far as the Southerly Plant effluent. In addition, large quantities of black heavy oil floating in slicks, sometimes several inches thick, are observed frequently. Debris and trash are commonly caught up in these slicks forming an unsightly floating mess. Anaerobic action is common as the dissolved oxygen is seldom above a fraction of a part per million. The discharge of cooling water increases the temperature by 10 to 15°F. The velocity is negligible, and sludge accumulates on the bottom. Animal life does not exist. Only the algae grows along the piers above the water line.

The color changes from gray-brown to rusty brown as the river proceeds downstream. Transparency is less than 0.5 feet in this reach. This entire reach is grossly polluted.

There have reportedly been at least thirteen fires on the Cuyahoga River, the first occurring in 1868. The largest river fire in 1952 caused over $1 million in damage to boats and a riverfront office building. Fires erupted on the river several more times before June 22, 1969, when a river fire captured the attention of Time magazine, which described the Cuyahoga as the river that "oozes rather than flows" and in which a person "does not drown but decays."

The 1969 Cuyahoga River fire helped spur an avalanche of water pollution control activities resulting in the Clean Water Act and the creation of the federal Environmental Protection Agency.