[2]: 1, 114 At the time, the United States Government was principally financed by duties on imports and exports (the federal income tax did not become a permanent feature of the US system until 1913).
The appropriate import and export taxes on commercial items were determined at customhouses maintained by the federal government at various ports of entry.
[2]: 77, 123 In 1830, the US Senate requested the Secretary of the Treasury to ‘cause a comparison to be made of the standards of weight and measure now used at the principal custom houses in the United States, and report to the Senate at the next session of Congress.’[3] To carry out this mandate, the Treasury Secretary appointed Hassler, who found[4]: 1 that (as was suspected) large discrepancies existed among the weights and measures in use at the principal customhouses at different US ports.
The original English standard, in turn, was made in 1758, but was then damaged beyond the point of usability in the great fire of 1834.
They were therefore accepted by the Office of Weights and Measures (a predecessor of NIST) as length standards of the United States.