"first of May," on which the opening of the season of flowers and fruit formerly was celebrated throughout Europe, mid-13c.; see May + day (n.). May Queen "girl or young woman crowned with flowers and honored as queen at the games held on May Day," seems to be a Victorian re-invented tradition; the phrase Queen of Maij is attested from c. 1500.
May Day's association with communism (and socialism and anarchism) dates to 1890. A U.S. general strike for an eight-hour workday began May 1, 1886, and culminated in the Haymarket bombing affair in Chicago on May 4. By 1890 strikes, protests, and rallies were being held in Europe by socialist and labor organizations on May 1, at first in support of the eight-hour day, more or less in commemoration of the 1886 strike.
1820, from German Walpurgisnacht, witches' revel, especially on the Brocken in the Harz Mountains, on May-day eve, literally "the night of (St.) Walpurgis," from Walburga, English abbess who migrated to Heidenheim, Germany, and died there c. 780; May 1 being the day of the removal of her bones from Heidenheim to Eichstädt.
"day on which a memorial is made," by 1819, of any anniversary date, especially a religious anniversary; see memorial (adj.). As a specific end-of-May holiday commemorating U.S. war dead, it began informally in the late 1860s and originally commemorated the Northern soldiers killed in the Civil War. It was officially so called by 1869 among veterans' organizations, but Decoration Day also was used. The Grand Army of the Republic, the main veterans' organization in the North, officially designated it Memorial Day by resolution in 1882:
That the Commander-in-Chief be requested to issue a General Order calling the attention of the officers and members of the Grand Army of the Republic, and of the people at large, to the fact that the proper designation of May 30th is Memorial Day and to request that it may be always so called. [Grand Army Blue Book, Philadelphia, 1884]
The South, however, had its own Confederate Memorial Day, and there was some grumbling about the apparent appropriation of the name.
The word "Memorial" was adopted by the Maryland Confederates shortly after the war, and has been generally used throughout the South. It is distinctively Confederate in its origin and use, and I would suggest to all Confederate societies to adhere to it. The Federals' annual day of observance is known as "Decoration Day," having been made so by an act of Congress, and the 30th day of May named as the date. In Maryland there is annually a Decoration Day and a Memorial Day. The two words are expressive not only of the nature of the observance, but also of the people who participate therein. [Confederate Veteran, November 1893]
"the spirit of the sea," 1751, first mentioned in Smollett's "The Adventures of Peregrin Pickle" as ("according to the mythology of sailors") an ominous and terrifying fiend who "presides over all the evil spirits of the deep, and is often seen in various shapes, perching among the rigging on the eve of hurricanes, shipwrecks and other disasters." Davy Jones's Locker "bottom of the sea," is 1803, from nautical slang, of unknown origin; second element may be from biblical Jonah, regarded as unlucky by sailors.
You know him. The one who sits on the back seat and tells the driver what to do. He issues a lot of instructions, gives advice, offers no end of criticism and doesn't do a bit of work. ["The Back Seat Driver," Wisconsin Congregational Church Life, May 1923]
1942, "the Allied nations at war with the Axis powers;" the international body (officially the United Nations Organization) was chartered in 1945.
Such negotiation as may occur in New York is not conducted within the walls of the tall building by the East River: it is carried out elsewhere, in accordance with those principles of courtesy, confidence and discretion which must for ever remain the only principles conducive to the peaceful settlement of disputes. [Harold Nicholson, "The Evolution of Diplomatic Method," 1954]