Southern Maryland Catholics gathered in Leonardtown on Sunday for a festive outdoor family mass that both welcomed Archbishop James A. Hickey and celebrated their region's history as the site of the beginnings Catholicism in America.

In the last of a series of welcoming events for the new archbishop, Hickey told 500 persons who had gathered for the late afternoon mass that soon after being named to the Washington archdiocese, "I began studying the history of Maryland, especially Southern Maryland . . . with its history of freedom of religion."

Hickey reviewed for his listeners the arrival, in March 1634, of the Jesuit missionary the Rev. Andrew White and a group of Catholic colonists who landed on St. Clements Island and subsequently established Catholic settlements.

"If Father White were standing here today I think he would remind us of the importance of our faith . . . and that our ancestors came to the new world for freedom," the archbishop said.

The area has a high percentage of black Catholics -- probably 20 percent of the worshippers at the mass were black -- and although churches and church schools in Southern Maryland are technically integrated, some racial tensions continue to exist.

In his homily, Hickey appeared to go out of his way to address the problem with an admonition to Catholics of the area to work for "fellowship and full equality for all human beings."

Noting that the nation, which "once knew the curse of slavery," has made great progress in attacking racial inequities, he added that for Christians, "our greatest remedy is that all of us, in all we do, honor and respect every human being." He urged his listeners "to purge from our hearts in our day, every trace of racism and discrimination."

Jim Siemer, 20, who sought to distribute antidraft registration leaflets during the social hour and informal reception after the mass, was twice evicted by Knights of Columbus members acting as ushers, even though the neatly dressed youth gave assurances that he could not create a disturbance.

Few of the worshippers were aware of the confrontation and a spokesman for the archbishop said later that Hickey knew nothing about it. "I'm sorry nobody asked us," said the Rev. Maurice Fox, the archbishop's secretary. "He's a fine boy and he maintains a valid position" in his antiwar stance, Fox said of the youth who represented Pax Christi, an international Catholic peace movement.

Many of the worshippers came in family groups. Clustered on blankets and lawn chairs in patches of shade on the grounds of St. Mary's Academy, they gave a relaxed, picnic atmosphere to the gathering.

As soon as the mass was over, many lined up to shake hands and exchange greetings with their new archbishop, while others munched homemade ham and biscuit sandwiches and cookies and listened to a variety of local talent entertain. Clowns handed out "Welcome Archbishop Hickey" balloons and played gentle pranks on delighted children.

"It's wonderful," said Frank Valenta of La Plata, as he surveyed the scene. "It's just like when we went to Washington last year to see the Pope," he said.