[2] The purpose of the act was to vaccinate the American Indians against smallpox to prevent the spread of the disease.

[3] Members of Congress appropriated US$12,000 (approximately $400,000 in current money) to vaccinate them.

[5] Congress allocated $12,000 for the entire program, to be administered by Indian agents and sub-agents.

Some US army surgeons refused to participate due to the lack of funds, leaving agents themselves and others with no medical training to produce and administer vaccines.

As a result, a few years later, smallpox killed 90% of the Mandan Indians, who had been excluded from the act.