FIGURE 20.2 Expansion in U.S. Trade, 1870–1910 Between 1870 and 1910, American exports more than tripled. Imports generally rose, but they were held in check by the high protective tariffs championed by Republican presidents from Ulysses S. Grant to William Howard Taft. A decline in imports is particularly noticeable after the passage of the prohibitive McKinley tariff in 1890.