This is the birthday of the U. S. Coast Guard. On this day in 1790, the President of the United States, George Washington, at the behest of the Secretary of the Treasury, Alexander Hamilton (portraits on the $1 and $10 bills, respectively) signed the bill establishing the Revenue-Marine Service under the command of the Treasury, to eradicate the rampant smuggling and evasion of tariffs by the good citizens of the new country.
This was not an easy task, as those same good citizens had been engaged in smuggling and other illegal activities since - well, before the colonies became states, that's for certain. And when the new country has at least 1600 miles of coastline (multiply it by 16 if you want to count the inlets, bays, and navigable rivers), there's plenty of room for duty and tariff evasion. Ten ocean-going cutters were ordered and built to handle it all, augmented by the smaller vessels utilized by the customs collectors. The customs boats were equipped for ports, bays, and shorelines only; they could not go out to sea. The cutters, sailing well away from the shoreline, formed the first line of defense against the extensive smuggling operations.
Cutter captains were - at least on paper - answerable to the customs officials of the ports from which they sailed, but their orders were at once stringent and vague. They were to board incoming and outgoing vessels, and check their papers, ensuring first that the cargoes were legal and then that they were properly documented. They were to seal the cargo hold of incoming vessels (once the cargoes are checked for accuracy, we don't want anything - ahem - removed before the vessel makes port). And they were to seize all vessels not in compliance with the law.
But they were also to remember that these men were independent citizens, who might reasonably take umbrage at any officiousness on the part of the government (yeah, like that's changed)... so their boarding of ships and checking of papers and sealing of holds and seizing of vessels must all be done diplomatically - as much as possible.
On top of that, they were to enforce any and all quarantines and embargoes, carry passengers as needed, chart the shoreline, and take supplies to the lighthouses.
[With so little to do, I'm surprised the crews didn't mutiny for more work. That is sarcasm, for those who missed it.]
After a few more changes of name - and a lot more coastline to cover - the service was joined with the Lifesaving Service in 1915 to become the United States Coast Guard, one of the seven uniformed services.
For articles on Coast Guard history, please see the Historian's Office page and Wikipedia's page. The Coast Guard page has more articles, including the current whereabouts of their tall ship Eagle.