Are you referring to the Dingley Act of July 24, 1897? It stayed in effect until the Payne-Aldrich Tariff Act of 1909. I did mistype the date I had intended, which was the McKinley act of 1890.

The Dingley tariff was an amendment to the Wilson-Gorman act of 1894 which was amending the McKinley act.

Pete