Between 1750 and 1850, colonization grew the Atlantic Coast’s population from hundreds of thousands to two million people. Shad fishing became more commercialized and efficient, with larger crews and seine nets. In the 1840s, fishermen were removing more than 40,000 tons of shad from the rivers annually.
The demand depleted the American shad population precipitously. By the end of the 19th century, the annual catch of shad was just 4,000 tons of shad. Overfishing wasn’t the only culprit in the population drop. Dam construction on Virginia’s rivers in the late 19th century resulted in the loss of access to substantial portions of natural spawning grounds for shad. Pollution also had an impact.