Despite its relatively short length, the Gowanus Canal was a hub for Brooklyn's maritime and commercial shipping activity. At its busiest, as many as 100 ships a day transported cargo through it. In addition, the industrial sector around the canal grew substantially over time to include stone and coal yards; flour mills; cement works, and manufactured gas plants; tanneries, factories for paint, ink, and soap; machine shops; chemical plants; and sulfur producers. All of these industries emitted substantial water and airborne pollutants. Chemical fertilizers were manufactured along the canal soon after the Civil War.