Jesse L. Jackson, expressing eagerness to help defeat President Reagan, met here yesterday with 14 southern Democratic state chairmen and representatives of the party's presidential campaign to draft a strategy for winning the South in November by educating blacks and whites to unite on their common issues.

Jackson, who until this week had been on-again, off-again about supporting the Walter F. Mondale-Geraldine A. Ferraro ticket nominated at the July convention, helped initiate the meeting, which was hastily organized in the last two days by Virginia Chairman Alan Diamonstein.

Among those at the 2 1/2-hour session, which participants described as "historical," were Richard Moe, a long-time Mondale friend and political adviser; Jim Quackenbush, Mondale's southern regional coordinator, and Rep. Gillis W. Long (D-La.), representing the House Democratic Caucus.

The chairmen formed two committees -- one to draft a campaign agenda for the South, the other to carry it out.

The main elements will attempt to overcome racial and sectional divisions and educate southern Democrats on their common economic interests, and will continue a drive to register eligible voters, particularly blacks.

"The issues of segregation have been overcome and it is time to move from the racial battleground to the economic common ground," Jackson told reporters at a briefing after the closed session. "Slavery, legal and social segregation, school segregation, public accommodation and the right to vote -- these troubles have finally been overcome and conquered . . . . We need an economic agenda that can meet human needs, have more commitment to quality education, stopping slave labor jobs from being exported abroad, enfranchising women, stopping the South from being used as a toxic waste dump . . . . These are not black-white issues."

Mondale telephoned the meeting from his home in North Oaks, Minn., to offer encouragement and appreciation.

"Mondale and Ferraro have shown that they understand the importance of the South by spending so much time there," Long said. "He's been there eight times already, and he's been talking of our common economic issues."

Jackson chimed in to declare, "The lines of communication have never been clearer."

The participants agreed that they face a major problem in persuading Democrats to look beyond Reagan's personal popularity and focus on their economic self-interest.

"It's true that the president is popular in the South, but his programs are not," Diamonstein said. "We've got to get people to focus on those and how Reagan's policies affect them.

As for getting out the vote, most of the participants were familiar with the numbers from 1980, when Reagan won all the South except Georgia, mostly by small margins.

"There are 19 million eligible black voters, 12 million registered," Jackson said. "Those newly registered blacks in coalition with whites, Hispanics, Jews, working people, women and senior citizens represent a political dynamic that is the opposite of apathy. Eight and a half million unemployed, 30 million young people who are standing in line waiting to kill or be killed in Central America, people in food stamp and cheese lines, they all have a reason to vote."

Jackson was asked if he had finally endorsed the Mondale-Ferraro ticket.

"If you indicate that you are going to embrace the ticket and campaign for the ticket and vote for the ticket, that could translate to endorse," he responded.

Earlier in the day, after a two-day Chicago meeting of leaders of his unsuccessful campaign for the nomination, Jackson made a strong plea for them to enthusiastically back the Democratic ticket.

"When one looks at the live options in this campaign," he said, "the courses of Reagan and [Vice President] Bush, of the aristocracy, of the rich and for the privileged must be challenged by the masses. We have a chance; we must exhibit our political option on Nov. 6."