UPTON, Mass. – Laurence A. Cooper Jr., 89, of Upton and formerly of Southborough, Mass., died early Tuesday, Dec. 9, in his home after a long illness. He was a retired chemical engineer and the husband of Janice E. (Temple) Cooper.

He was born in Lewiston, a son of the late Laurence A. and Alice L. (Tarr) Cooper. He grew up in Auburn, where he was a 1937 graduate of Edward Little High School, and earned an engineering degree from the University of Maine at Orono in 1941.

He worked on the production of plutonium for the Manhattan Project during World War II. He then spent many years in research and development at Bay State Abrasives and Diamond International Paper Co. before retiring in 1984.

He lived in Southborough for many years before coming to Upton in 1985, and enjoyed many summers in Maine. His hobbies included gardening, photography, and bowling; and he was a member of the Upton Historical Society, the Blackstone Valley Gardeners, and a former president of the Upton Senior Bowling League.

In addition to his wife of 35 years, he leaves three children, Lynn Blake and her husband, Henry, of Houston, Texas, Leslie Morenus and her husband, David, of Jacksonville, Fla., and Jeffrey Cooper and his wife, Andrea, of Colorado Springs, Colo.; three stepchildren, John Page and his wife, Susan, of Willard, Vt., Steven Page and his wife, Victoria, of Sharpsburg, Ga., and Susan Page Barnhart and her husband, Brian, of Westboro, Mass.; one brother, Stuart Cooper and his wife, Esther, of Sumner; nine grandchildren; 12 step-grandchildren; 11 great-grandchildren; and many nieces and nephews.

His first wife, Natalie G. Cooper died in 1971, after 28 years of marriage. He was also the father of the late Laurence A. Cooper III, who died in 2006; the brother of the late Patricia Perry and Jean May; a step-grandson and step-great-grandson, also predeceased him.