This is the only known document signed by four living presidents: Washington, Jefferson, Madison, and John Adams. In all, it was signed by 30 subscribers, 12 of whom were elected APS Members—including the four presidents.

It was drafted by President Jefferson to raise money for an expedition to find a route to the Pacific—this was 11 years before Louis & Clark (1804-1806). Each signer wrote the amount of money they pledged next to their name. 

The expedition was to be led by French botanist Andre Michaux. He offered to explore the sources of the Missouri River and search for rivers that flowed into the Pacific. Ultimately, the expedition was called off due to diplomatic difficulties with France, which owned much of the territory to be explored.