United States. Department of the Treasury. "Letter of the Secretary of the Treasury to Officers of the Customs," in United States. Department of the Treasury. "Annual Report of the Secretary of the Treasury on the State of the Finances for the Year 1889," Annual Report of the Secretary of the Treasury on the State of the Finances (1889) : 994-994. https://fraser.stlouisfed.org/title/194/item/5535/toc/296616 , accessed on April 25, 2024.