How do you sum up the meaning of being a member of the Daughters of the American Revolution, Mimi McDonald of Michigan?

"Very easily. It's a way to show my love for my country."

McDonald, dressed in a white gown like other pages (members who are between 18 and 35), stood in a hallway of Constitution Hall last night directing dressed-up Daughters of the American Revolution to their seats for the opening evening of the 92nd Continental Congress.

McDonald has been in the organization for 23 years, starting as a member of the National Society, Children of the American Revolution. She's 28 now and one of the younger members in the group. She was excited about the evening, as were most of the members, all bearing ribbons proving a relationship to someone who served in the American Revolution.

Last night's keynote speaker, Vice President Bush, told the Daughters, "somehow it seems more . . . ah . . . cozy, meeting with this Congress than meeting with the Congress on Pennsylvania Avenue."

He also praised some of the DAR's achievements, citing their Arbor Day Award given in 1982 for planting trees in towns throughout the country.

"Speaking of trees," said Bush, "I just want to make it clear that there's no truth to the rumor that James Watt refused to celebrate George Washington's birthday because he felt guilty about the chopping down of a tree."

Earlier in the evening, as the hall filled to capacity, the U.S. Marine Band played marches nonstop. Then the grand procession started.

"At a certain point, they're going to drop that flag and this place is going to go crazy," one elderly Daughter in the second row said.

Sure enough, as DAR president general Patricia Shelby entered the middle aisle, a giant flag dropped from the ceiling and waved gracefully over the crowd. Ooohs, aaahs and cheers went up. Stars and Stripes Forever started again for the umpteenth time. Cameras clicked in the audience.

Then an invocation, the first and fourth stanzas of the National Anthem, the Pledge of Allegiance and The American's Creed recited in unison, a brief message sent by President Reagan and the introduction of Bush.

In his address, Bush pointed out the group's activities in supporting education. He described past government funding of education, and called for a "renewal" of education demanded "by the people, not imposed by the government."

Before being escorted out, Bush denounced as "cowardly" the Monday bombing of the U.S. Embassy in Beirut.

"Our president in September offered a plan for peace in the Middle East. No one agrees totally with it, but on every side it is agreed that the ingredients for peace are there. But what we must remember is that we must not pull back or surrender as the greatest country in the world."

The Daughters applauded and Shelby took the podium for the official welcome for the week, which will include the election of her replacement.

"It has been said, and rightly so, that there's no more American gathering in the length and breadth of this land than a Continental Congress of the Daughters of the American Revolution."