Based on the Coast Guard Historian’s timeline, https://www.history.uscg.mil/research/chronology/
With inspiration from Mike Kelso

Coast Guard Cutter Aspen crew reestablishes a buoy while conducting Aid to Navigation operations off the coast of Humboldt Bay. The crew of the Aspen traveled to Humboldt Bay to recover displaced aids to navigation and attempted to restore missing navigational aids to assist mariners in transiting the Humboldt Bay entrance in Samoa, California. (U.S. Coast Guard photo by Seaman Ryan Estrada /Released)

1850  An Act of Congress (9 Stat. L., 500, 504) provided for a systematic coloring and numbering of all buoys for, prior to this time, they had been painted red, white, or black, without any special system.  The act “prescribed that buoys should be colored and numbered so that in entering from seaward red buoys with even numbers should be on the starboard or right hand; black buoys with odd numbers on the port or left hand; buoy with red and black horizontal stripes should indicate shoals with channel on either side; and buoys in channel ways should be colored with black and white perpendicular stripes.”

1850  An Act of Congress (9 Stat. L., 500, 504) gave legal authority for the first time for the assigning of collectors of customs to lighthouse duty. Section 9 of this act authorized the Secretary of the Treasury to assign to any of the collectors of customs, the superintendence of such lighthouses, beacons, lightships, and buoys as he might deem best. The act also stipulated that no collector of customs whose annual salary exceeded $3,000 a year should receive any compensation as disbursing officer in the Lighthouse Establishment and, in no case, was the compensation of the collectors of customs for disbursements in the Lighthouse Service to exceed $400.00 in any fiscal year.

The Coast Guard cutter Boutwell,’ foreground, is seen escorting the Liberian-flagged vessel ‘Command’ Tuesday, Oct. 6, 1998, in international waters. AP Photo by US Coast Guard

1998  An oil spill along the coast of California off San Francisco was traced to the 717-foot Liberian-flagged tanker Command.  A Coast Guard boarding team took samples of her cargo and matched it to that found along the coast.  A Coast Guard spokesman noted: “This is the first time the Coast Guard has pursued an oil spill investigation into the international arena to the extent of stopping and boarding a vessel on the high seas, with permission of the vessel’s flag state.” (“Coast Guard investigators tracked the 717-foot ship and boarded it off the coast of Central America. They allegedly matched the chemical fingerprinting to oil collected from the first fuel leak with the slick that reached the San Mateo coast.”)