It was like a gathering of the clans outside the Metro headquarters building at Fifth and F streets NW at noon yesterday. Hundreds who knew him, were related to him, worked with him and observed him were there for the dedication of The Jackson Graham Building, as the transit authority's operating center is now officially known.

Graham, the retired Army Corps of Engineers general who reigned nearly 10 years until 1976 as Metro's brilliant and often imperious first general manager, died last March at the age of 75. Metro Scene suggested naming the eight-story building in his honor and the Metro board swiftly agreed.

"It's fitting that the house that Jack built will be named for him," observed John Warrington, Graham's former special assistant, in a message relayed from a sickbed. Carlton R. Sickles, senior member of the Metro board, said Graham, if he were still alive, probably would have resisted the naming. But, Sickles added, probably "he would have been pleased . . . . "

Graham's widow, Mabel Lee, who lives in California, was there with their two grown children, son Jack and daughter Dixie Johnston and their spouses. Mrs. Graham, Sickles, Metro General Manager Carmen E. Turner and Graham's old Army sidekick, retired Brig. Gen. Roy T. Dodge, Metro's first construction chief, pulled the drawstrings that revealed the name on the building facade.

But fame can be fleeting.

After the ceremony, four young women -- who wouldn't yet have been in their teens when Graham was active -- walked up the street and looked at the sign.

"The Jackson Graham Building," one observed. "Who was he?"

"Who knows?" responded another. "Somebody must have made an announcement."