The centralization of animal slaughter in stockyards in places like Chicago and Cincinnati, and the development of railroads, meant that collection of animal byproducts was also largely confined to those yards. The result was the decline of urban bone pickers, and the rise of mass sales of byproducts, including bone and hides, by the 1870s. Stockyards had the capacity to sell bone by the ton, rather than the bushel.
Though brush manufacturing began in the United States in 1808, most brushes were made in Britain or France. Beginning in the 1870s, when stock yards and railroads made gathering and shipping bones more efficient, the US shipped most of its animal bone abroad for brush manufacture. The primary toothbrush manufacturing nations were Britain and France until World War I, when Japan took control of the market. A US tariff report in 1918 reported that it had always