It was a media event of sorts, more exciting for its technology than for the Thanksgiving message delivered laconically by the man sitting in front of the microphones in his White House study 55 years ago last night.

On Nov. 23, 1927, according to a contemporary press account, President Calvin Coolidge spoke "over a huge radio chain . . . reading the text of his Thanksgiving Day proclamation, issued earlier in the month." It was, the account reported, "the first time a president has been able personally to appeal to the country to observe the festival."

Already, in a gesture that would be appreciated by today's civil servants, the president had given federal workers half a day off on the day preceding the holiday. They did not, however, get any time off on Friday.

It was somehow appropriate that Coolidge, the quintessential Republican Yankee, got first crack at a coast-to-coast Thanksgiving presidential message.

After all, Thanksgiving, as we now recognize it, began as a Northern -- and hence a predominantly Republican -- holiday, given the political complexion of the country at the time.

Although first proclaimed by President George Washington, it was attacked as a "New England holiday" in the South and other areas where Yankees were held in less than high esteem. So it languished as a national event, and was observed for decades in various states and here in Washington at local whim, sometimes becoming a source of political controversy.

Thanksgiving did not become even nominally a national holiday until proclaimed one by Republican President Abraham Lincoln in 1863, in the midst of the Civil War. All his successors have followed his precedent.

Despite early objections to the New England origins of the traditional Thanksgiving festival, it gained popularity among merchants in Washington -- which, although considered to be in the South, drew its population from the entire nation. In 1845 a newspaper here advertised the availability of potables for the Thanksgiving feast: "Sixty barrels of white wine, 40 barrels of champagne and New York cider, all by recent packet via the seaport of Alexandria."

That was the year of the City of Washington's first official, local Thanksgiving proclamation, issued by Mayor W.W. Seaton. That document sought, among other things, "to preserve and strengthen . . . our national union."

But the national union was fraying over the issues of slavery and states' rights.

By 1849, according to the late local historian John Clagett Proctor, Washington Alderman C.W.C. Dunnington moved to defeat a resolution declaring a Thanksgiving holiday. Obviously a southern sympathizer, Dunnington asserted that New Englanders would doubtless spend the day promoting "sedition, insurrection and disorder"--a euphemism for encouraging blacks to rise against the bonds of slavery.

Dunnington won. The Thanksgiving resolution was defeated, 7 to 5. But Democratic Mayor James G. Berret ignored the action and issued a mayoral proclamation designating a day of celebration, reportedly under pressure.

Lincoln himself, during the Civil War, heeded a protracted editorial campaign by Sarah J. Hale, the nation's first woman magazine editor, and issued Thanksgiving proclamations in 1863 and 1864.

After Lincoln's assassination, a delegation of former New England residents who worshipped in Washington's First Congregational Church called upon President Andrew Johnson on Oct. 25, 1865, and asked him to follow Lincoln's precedent and appoint a day for yearly Thanksgiving.

That was done. Thanksgiving continued to be a national and District of Columbia holiday by presidential proclamation -- but not by federal law -- until 1941, when Congress by law designated the fourth Thursday of each November as a federal holiday. The vote by Congress was a rare congressional revolt against President Franklin D. Roosevelt, who had proclaimed in 1940 that the holiday should be observed a week earlier, ostensibly to lengthen the Christmas shopping season.

Until then, government workers and businesses here had to wait each year to confirm that the White House had issued the necessary document declaring a holday.

The custom of presidential proclamations continues. President Reagan got that ceremonial detail of his office out of the way early this year, issuing his proclamation on Sept. 25.