Four weeks ago, Jean Lentz decided to take a 10-month leave from her high-paying job as an IBM executive in Dallas so that she could move to Virginia and work full time for passage of the Equal Rights Amendment.

Yesterday, Lentz, 40, now part of a small army of ERA recruits who have relocated just to work for the amendment, stood on the steps of the Lincoln Memorial along with more than 1,000 other women, rallying in support of the movement's final push to win ratification of the amendment before the June 30, 1982 deadline.

Thirty-five states have ratified ERA, but the constitutional amendment will die unless three more states approve it in the next 261 days, according to the National Organization for Women, organizers of the rally.

Billed as "A Call to the Nation's Conscience," the Columbus Day rally featured spirited speeches by former first ladies Betty Ford and Lady Bird Johnson and culminated a four-day NOW conference in Washington aimed at bolstering the ERA effort in the 15 states which have not ratified it. U.S. Park Police estimated the crowd at about 1,000, while organizers claimed 3,000.

"As a woman and as a Republican, I don't see how we can continue to stand up and be proud if we have not guaranteed the rights of half our population," said Ford, speaking beneath a 30-foot green banner bearing the wording of the proposed amendment. "We have gotten past the point of asking. We are at the point of demanding recognition of our right to equality."

Johnson drew parallels to the civil rights struggles of the 1950s and 60s, saying, "The fight for civil rights was won because it was the right thing to do and was long overdue. The Equal Rights Amendment is the right thing to do and is long overdue . . . I am proud to say that the menfolk and womenfolk of my family, past and present, are supporters of ERA."

Lentz, who like hundreds of others wore a green NOW T-shirt over her street clothes and who left the 11 a.m. rally hoarse from yelling, is one of dozens of NOW recruits who have left jobs, colleges, and families to work in "unratified states" for ERA, according to NOW press secretary Judy Murphy. She said several hundred volunteers offered to do the same at the four-day conference at the Shoreham Hotel.

Lentz, a District of Columbia native who was transferred to Dallas 18 months ago, said she left her job "because I feel it is essential to put women in the Constitution, to give them a foundation on which to guarantee their rights."

She said she grew frustrated in recent months because she could not work full time at IBM while trying to also work long hours for ERA. "I had really started to question my own position in life," she said, "I felt if I was ever really going to do something for the women's movement, this was it."

She said she is now directing the "Fairfax Project," a joint effort of the state's NOW chapter and the Virginia Women's Political Caucus and a job for which she receives only living expenses. It is aimed at winning seats for pro-ERA candidates in Northern Virginia in next month's House of Delegates elections, and then winning the subsequent battle over ERA ratification. Virginia and Mississippi are the only unratified states with legislative elections this year and NOW has "high hopes" for Virginia, she said.

Borrowing tactics from Mormon missionaries, hundreds of "ERA missionaries" have gone door to door in Utah lobbying for ERA, Murphy said. She said plans are to expand that effort to other states.

During the rally, most in the crowd shouted their support or waved green-and-white banners, but not all onlookers were happy. Said an Army security guard assigned to aid Secret Service agents protecting the former first ladies: "Look, let's just say I wouldn't be here if I didn't have to be."