The 10-year battle over passage of the Equal Rights Amendment ended yesterday with vows of continuing political warfare from its supporters and expressions of triumph from its opponents.

The occasion was marked in the nation's capital with both eulogies and celebrations.

The National Organization for Women held a press conference and rally in support of those who had worked for passage of ERA. Several women who recently fasted for 37 days in support of women's rights legislation began a two-day demonstration at the National Archives. Maureen Reagan, daughter of the president, voiced her continued support for the measure.

On the other side of the issue there were feelings of joy and vindication. Phyllis Schlafly, the most visible opponent of ERA in recent years, lashed out at the measure's supporters during a press conference yesterday morning. And as evening fell, Schlafly threw a festive "Over the Rainbow Celebration" at the Shoreham Hotel.

The common theme of the day's events was that feelings remain strong on both sides, that the battle over women's rights did not die with the proposed constitutional amendment. ERA's time limit expired yesterday after the measure had been ratified by 35 states--three short of the number required.

"We will never give up, we will never give in," sang an estimated 2,000 ERA supporters at the NOW rally, which was held in Lafayette Square yesterday afternoon. Members of the crowd, brightly dressed in green and white--the colors of the ERA campaign--claimed that they were on the threshold of a new political movement.

Rally participants included some 700 nurses who are in town for the American Nurses Association convention. The ANA, a longtime supporter of ERA, sent a letter to Schlafly yesterday contending that the majority of American women will continue to support ERA.

"We are ending this campaign stronger than we began," said Eleanor Smeal, president of the National Organization for Women. "We are a majority. We are determined to play majority politics . . . . We are not going to be reduced again to the ladies' auxililary," Smeal said.

Smeal also said that she would not seek or accept reelection as NOW president, and laid to rest rumors that she favored the creation of an independent women's political party.

At a NOW press conference yesterday morning, Smeal said that the new approach would be to work for the defeat of anti-ERA lawmakers and push for more women in local and national politics. NOW released a list of 137 state legislators to be targeted for defeat, and Smeal said the group hopes to raise $4 million over the summer for its campaigns.

The National Women's Political Caucus yesterday released its own list of 12 targeted state legislators, including Virginia House Speaker A.L. Philpott.

Smeal said that failure to rewrite laws that favor women means that women will continue to be underpaid, will suffer disproportionately from cuts in social security and "divorced women will continue to get ripped off."

Rep. Don Edwards (D-Calif.), one of ERA's most prominent supporters in Congress, said in an interview at the rally that on July 14 more than 100 House and Senate members would gather on the steps of the Capitol to reintroduce the ERA. He estimated that there are 150 cosponsors for the bill in the House and about 40 in the Senate.

As before, the new ERA proposal would have to be passed by a two-thirds vote in Congress. "It won't pass in this Congress," Edwards said, but he said he is confident that supporters will recover lost ground in the 98th Congress.

In a carefully worded speech at the National Press Club, Maureen Reagan went out of her way not to embarrass her father. "I don't have a very good explanation of why the president doesn't support the ERA," she said in answer to a question. "I know he did at one time and changed his mind, and I've always been very disappointed."

As supporters of ERA vowed to regroup, ERA opponents celebrated their victory. Schlafly, president of Stop ERA, told a crowded morning press conference that ERA "is dead for now and forever in this century," and said the nation can now enter "a new era of harmony betwen women and men."

She ridiculed attempts of ERA supporters to keep the measure alive, and said that the polarizing affect of the ERA issue was not good for the country.

"They know ERA can't be passed in the near future. It's simply a whipping boy, a media event, a political tool," she said.

"It is difficult to sell the notion that ERA would be a benefit to women when the one certain effect admitted by everyone is that young women would be forced into the Army against their will in the name of equality," Schlafly said.

"We won and it really wasn't even close," Schlafly said. "We've been doing our political work better than the other side." The ERA measure, she said, had been supported by "vicious people."

Schlafly continued the anti-ERA forces' celebration last night, hosting a gala at the Shoreham Hotel.