Richard R. Beeman, 74, a University of Pennsylvania historian and a trustee of the National Constitution Center, who revered America's founding document and spent decades teaching its creation and complexities, died Monday, Sept. 5, of amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease.

Dr. Beeman, of Moylan, was the John Welsh Centennial Professor of History at Penn, where he was a faculty member for 43 years.

"It has been my great privilege during those years to teach thousands of bright Penn undergraduates and graduate students the subject I love - the history of the American Revolution and Constitution," Dr. Beeman wrote on his website.

During his time at Penn, Dr. Beeman also was chair of the history department and dean of the College of Arts and Sciences, among other posts.

He held a doctorate in history from the University of Chicago.

A lover of animals - dogs particularly - Dr. Beeman served on the board of directors of the Delaware County SPCA in 2005 to help "straighten out controversial difficulties with funding and management," said daughter Kristin Dunning, a guidance counselor at Strath Haven High School in Wallingford.

Dr. Beeman wrote eight books and dozens of articles on U.S. political and constitutional history, winning the George Washington Book Prize for Plain Honest Men: The Making of the American Constitution (2009).

Dr. Beeman "made our national origins matter to generations of appreciative students, of which I was one," said Drew Gilpin Faust, president of Harvard University. "His books will keep his voice alive for many years to come."

The antithesis of the stereotypical stuffy professor, Dr. Beeman had a mirthful theatricality that he employed to bring history alive for his students.

He'd often show up for lectures in 200 College Hall, a cavernous, wood-paneled room, dressed as historical figures such as Davy Crockett, complete with musket and faithful dog, played by Dr. Beeman's Bernese mountain dog, named Chief Justice John Marshmallow.

"In another person, it would seem silly," said Beth Wenger, chair of Penn's history department. "But with Richard, it was just right. And the students adored him and worked hard for him."

Not content to limit his influence to the ivory tower, Dr. Beeman mentored primary- and secondary-school teachers, whom he hailed as "among the true heroes of our society, sharing their knowledge and passion for learning with young people."

Dr. Beeman wrote that "the future of our democracy is heavily dependent on shaping the minds of those young people in a way that they can be active and responsible citizens in our body politic."

That thinking was part of the reason Dr. Beeman became involved with the Constitution Center, which he called a true treasure, friends said.

Dr. Beeman "helped transform the Constitution Center into America's leading convening space for constitutional education," said Jeffrey Rosen, the center's president and CEO.

A tireless proponent of the Constitution, Dr. Beeman talked it up in the media, including NPR, MSNBC, and The Daily Show With Jon Stewart.

Born in Seattle, he told people that his fondest memories included growing up on the beach in Alamitos Bay, Long Beach, Calif. It was there that he developed a lifelong love of spending time near the water.

An athletic and energetic man, Dr. Beeman and a partner were Los Angeles city doubles tennis champions in 1962, Dunning said.

Dr. Beeman also was a marathoner, and proud of his under-3-hour, 10-minute time, said son Joshua, a university information security officer at Penn.

"I marvel at what he was able to do," Wenger said. "This is a tremendous loss."

In addition to his children, Mr. Beeman is survived by his wife, Mary Cahill; two grandchildren; his former wife, Pamela Butler; and a brother.

A memorial service will be at 5:30 p.m. Monday, Sept. 26, at the Constitution Center, 525 Arch St.

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