Coinciding with Britain's repeal of the Corn Laws, it led to an increase in trade and was one of the lowest tariffs in American history.
Democrat James Polk was elected President in 1844 over Henry Clay, a Whig who advocated a high tariff.
President Polk declared that reduction of the "Black Tariff" would be the first of the "four great measures" that would define his administration.
The Walker Tariff produced the nation's first standardized tariff: rather than setting fixed rates for specific items on a case-by-case basis, it established general schedules into which all goods could be classified, subject to defined ad valorem rates.
The bill reduced rates across the board on most major import items save luxury goods, such as tobacco and alcoholic beverages.