Dr. Bortz grew up in Cincinnati, graduating from high school there in 1937 and earning a bachelor's degree in history from the University of Cincinnati in 1941. He was drafted into the Army the next year and served first as a lieutenant and then as a captain in the military-supply Quartermaster Corps.
He saw Buchenwald, one of the German concentration camps, soon after the Army liberated it in 1945.
"While I was there, some of the prisoners were still there walking around," he recalled in a 2000 interview with a granddaughter. "They were literally skin and bones. If you've seen pictures of them, they were accurate. That was the first we heard of what they had done to the Jews."
After Dr. Bortz was honorably discharged in 1945, he immediately went back to school. His father, a Russian immigrant, impressed upon him the importance of education, and he had no intention of stopping with a single college degree.
He earned a master's degree in history at the University of Cincinnati in about 1947 and his doctorate in the same subject from Harvard University in 1950.
Dr. Bortz had hoped to teach at a university. But he received no full-time offers and his adviser, chalking it up to anti-Semitism, suggested the federal government as an alternative, said a son, Bruce Bortz.
So Dr. Bortz moved to Baltimore and became an Army historian, part of a team writing a multi-volume history of the Army in World War II. After 12 years, he took a job at what was then the Department of Health, Education and Welfare. Shortly afterward, he went to work for the Social Security Administration — building a foundation of information for all who study the country's largest domestic program.
As the agency's first and longest-serving historian, Dr. Bortz preserved early records, established its museum and launched its research archive, said Larry DeWitt, who retired from the same position last year.
"He was a pioneer in federal history," said Mr. DeWitt, who now lives in Arizona.
Dr. Bortz collected records, memorabilia and anecdotes, both serious and amusing. Among his museum displays, according to a 1982 United Press International profile of him, was a Social Security card that caused a lot of trouble. A manufacturer copied an employee's card from the 1930s and included it in thousands of wallets. Many of the new wallets' owners used that number instead of their own, by mistake.
Dr. Bortz, who remained as the agency's historian until he retired in 1985, found Social Security an engaging and worthwhile subject for study.
"He often made the point … that Social Security is really the most successful federal program ever created because it has all but wiped out poverty among old people," said Bruce Bortz, who lives in Baltimore. "And that's such a major societal accomplishment."
But Dr. Bortz's early desire to teach never faded. While he worked by day as a federal historian, he spent several nights a week in class as an adjunct history professor at the Johns Hopkins University and what was then Western Maryland College in Westminster.
Over the same period he wrote more than 100 book reviews, all for the Sun papers, largely the Evening Sun and Sunday Sun. He focused on histories of all sorts. In his first review in 1959, he considered two foreign-policy tomes and concluded: "Both books make the reader feel uncomfortable. For this reason alone they need to be read and pondered."
His appetite for books was ravenous. He amassed a collection of more than 10,000 — so many that his wife, the former Rita Gradsky, eventually decreed that any books coming in would have to be offset by an equal number going out. He gave thousands to the Johns Hopkins University library.
Reference books were among his favorites. He also owned many volumes about history, politics and journalism.
"We had bookshelves in pretty much every room," Bruce Bortz said, recalling his childhood. "He haunted bookstores, especially second-hand bookstores."
When Dr. Bortz retired from Social Security, he also retired from book reviewing and teaching. He and his wife traveled, seeing Europe and splitting the rest of their time between Baltimore and Florida.
The couple was married for 58 years, until Mrs. Bortz's death in 2009.
In addition to his son in Baltimore, Dr. Bortz is survived by a sister, Gittee Bortz of Cincinnati; another son, Jon Bortz of Potomac; and six grandchildren. In addition to his wife, he was predeceased by two sisters, Ann Loobman and Ruth Kravitz, and a son, David Lee Bortz.
A graveside ceremony was held Friday in Reisterstown. A celebration of life memorial is being planned.
Baltimore Sun researcher Paul McCardell contributed to this article.