William Curtis Sprong Jr., of Boston, Massachusetts, passed away peacefully on June 20, 2025, after a long journey with Alzheimer's disease, with his wife of over 30 years, Mary Moriarty Sprong, by his side.

A lifelong New Englander with a sharp intellect and a wry sense of humor, Bill was born on August 31, 1945, in Brockton, Massachusetts. Over the years, he made homes in Wellesley, Edgartown, Marblehead, and most recently, Boston. He was predeceased by his father, William Curtis (Curt) Sprong, mother, Elizabeth Scharfenberg, and sisters Marion and Jane.

Bill graduated from Dartmouth College and received a master's degree from Boston University. He went on to build a successful career as a Chief Financial Officer for several Boston-area companies and was especially proud to conclude his professional life at Grassroots Campaigns, where he used his financial expertise to support progressive causes that reflected his lifelong values.

Though understated and self-effacing, Bill had a quick wit and a deep love for language and humor, which he retained even as his illness progressed. He was a lifelong lover of folk music, classic rock, and the occasional sea shanty, and a self-taught guitarist. As a father, Bill led quietly and by example. He was always growing, building, or fixing something—projects that ranged from the whimsical (a solar-powered hot dog cooker) to the beautifully crafted (fine furniture pieces). While not every invention was entirely practical—the wooden cat carrier lives on in family lore—each reflected his precision, curiosity, and pride.

Bill was a loving father to Bill Sprong III of Bellevue, Idaho (married to Dana Gloor) and Emily Sprong Suiter of Seattle, Washington (married to Dan Suiter), and a proud grandfather to Huck, Grendel, Triona, and Kalina. He is also lovingly remembered by his extended family, including Brenda and Dave Welber, Jeff Welber, Kelsey and Jon Poorman and Alicia Buckheit-Walker, who all held special places in his life.

A private celebration of Bill's life will take place in late August. In lieu of flowers, the family requests that donations in Bill's memory be made to the Alzheimer's Association.