To the outside world, Eugene D. Genovese appeared to be in a constant war of words with fellow historians of the 19th Century South, especially those who took a starkly different view of the world than he. But to those who knew him, the Brooklyn-born historian couldn’t have been a better friend.

“He was famous as a controversialist, but personally he was a very generous man,” said David Moltke-Hansen, a former director of the Southern Historical Collection at the University of North Carolina. “He was very kind and thoughtful, but that did not always come across.”

Dr. Genovese, who had a history of heart problems, died Wednesday after a long illness, said his sister in law, Rebecca MacMillan Fox. A memorial service is scheduled for 10 a.m., Tuesday at the Cathedral of Christ the King, Atlanta. His body was cremated and H.M. Patterson & Son, Spring Hill, was in charge.

Dr. Genovese, and his wife Elizabeth Fox-Genovese, moved to Atlanta in 1986. By then he’d made a name for himself as one of the most well-known Marxist intellectuals in the country. His journey toward a different way of thinking seemed to start at a young age. When he was 15, he joined the Communist Party of the United States of America, and by 17 he was a party organizer in New York City. A little more than a decade later, his open support of the Viet Cong in the 1960s caused then-President Richard Nixon to try and have Dr. Genovese removed from the faculty at Rutgers University.

In a 1999, Dr. Genovese, who served briefly in the U.S. Army after college, told an Atlanta Journal-Constitution reporter that during the years he declared himself an atheist and professed allegiance to Marx, something nagged at him.

“I had long been troubled by the lack of a moral foundation in Marxism,” he said at the time. “It wasn’t clear to me that you could have that foundation without a belief in God. I mean, you can be an atheist and live a perfectly moral life, but what is it grounded in?”

In the early ‘90s, it appeared as if Dr. Genovese found a solution to his problem when he converted from atheism and Marxism to Roman Catholicism, shortly after his wife, a fellow atheist, made the conversion. But the reasons for his transition were not really related he said, explaining that his departure from atheism and Marxism was an “intellectual decision,” but his embracing of Roman Catholicism was a question of faith and “separate all together.”

Those who knew Dr. Genovese understood his passion for evolving though processes and exploration of ideas, Dr. Fox said.

“He was very much engaged in the world, and what was going on in the world, and that’s what drove him,” she said. “But, as strong as his own views were, as clear as they were, as well argued and deeply held as they were, he had incredible respect for people who had their own ideas, especially when those ideas didn’t agree with his.”

Dr. Genovese’s views were well documented in the several books and essays he authored over his career. His works include “Roll, Jordan, Roll: The World the Slaves Made,” published in 1976, and three books with his wife, who was an Emory University history professor and died in 2007.

“Without question he is one of the two most important historians of the 19th Century South,” Dr. Moltke-Hansen said. “We didn’t see eye to eye on political matters, but that didn’t keep us from being friends.”