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

May 16

1846  Eleven cutters were assigned to cooperate with Army and Navy in the Mexican War.  Cutters McLane, Legare, Woodbury, Ewing, Forward, and Van Buren were assigned to the Army.  Cutters Wolcott, Bibb, Morris, and Polk were assigned to the Navy.

1888  Secretary of Treasury was authorized to establish anchorage grounds New York Harbor, adopt suitable rules, and “take all necessary measures” for their enforcement.

1963  The Honorable Douglas Dillon, Secretary of the Treasury, at a ceremony at Cape May Receiving Center, awarded Life-Saving Medals to three enlisted men of the Coast Guard in recognition of their heroic action and performance of duty at the risk of their own lives.  Boatswain’s Mate First Class John C. Webb, coxswain of CG-36455 was awarded the Gold Life-Saving Medal and his crewmen, Engineman Third Class Anthony D. Lloyd and Seaman Ray Dwayne Duerre were each awarded a Silver Life-Saving Medal.  The awards were based on their rescue of three persons from a stranded pleasure craft disabled approximately two miles northwest of Cape Alava, Washington, on June 1, 1962.

May 17

1999  The Coast Guard “kept the peace” when the Makah Indian tribe hunted and killed a gray whale in Neah Bay, Washington.  The Makah were guaranteed the right to hunt whales in their 1855 treaty with the U.S.

May 18

1920  Coast Guard officers and enlisted personnel were granted the same pay, allowances and increases as the Navy.