A Maine family with fourth-generation ties to Bates College has donated $50 million to the Lewiston school, the largest single gift in its history and probably the largest cash gift to a college in Maine, campus officials said.

The donation came from Alison Grott Bonney and Michael Bonney, who both graduated from Bates in 1980.

“I believe that never in the history of the liberal arts tradition has a liberal arts education been more critical, when one thinks about the future of our society, than today,” Michael Bonney said.

The gift was announced as part of a five-year, $300 million capital campaign, the largest capital campaign in the school’s history.

“This campaign will be transformational for Bates,” President Clayton Spencer said Tuesday night at a campaign kickoff event held at the Museum of Fine Arts in Boston.

“The Bates Campaign provides us with the opportunity to secure the programs and values that have defined Bates for a century and a half and to shape new strategies for a new age,” she said.

Last year the Bonneys gave a $10 million gift, which was the largest single gift in the history of Bates at the time.

Other Maine colleges have received large donations, sometimes in objects, not cash. In February, the Colby College Museum of Art received its second gift of art valued at more than $100 million from longtime supporters Peter and Paula Lunder, which will launch the Lunder Institute for American Art.

Also this year, Colby received $25 million from the Davis Family Foundation to fund study abroad opportunities, and $10 million from Portland developer Joseph Boulos toward a new athletic complex.

Last year, Bowdoin College in Brunswick received a $10 million gift from college trustee David Roux and his wife, Barbara, to build a new center for studying the environment.

The University of Maine and University of Southern Maine are both launching major capital campaigns this spring.

Colby is also in fundraising mode this year, having recently announced it already had raised $100 million toward a $200 million state-of-the-art athletic center on campus that will include the state’s first Olympic-size swimming pool.

Michael Bonney has served as a Bates trustee since 2002 and as board chairman since 2010.

The Bonney family has ties to Bates going back to the 1920s, when Michael Bonney’s maternal grandfather graduated in 1927. Michael and Alison’s three children all graduated from Bates. Their $50 million gift, from the Bonneys’ family foundation, will help build new facilities and renovate existing science, technology, engineering and math facilities.

After graduating from Bates with a degree in economics, Michael Bonney began his career with Maine-based Hannaford Brothers, working in the supermarket chain’s pharmacy operation. He worked at several pharmaceutical companies before retiring in 2014 as CEO and director of Cubist Pharmaceuticals, which was acquired by Merck for $9.5 billion.

Bates spokeswoman Marjorie Hall said the college already has raised $168 million toward the capital campaign.

Of the $300 million goal, $75 million is earmarked for financial aid; $100 million for academic programs, including $24 million for eight endowed professorships; $65 million for student programs, including $25 million for athletics and $24 million for internship and work-related programs; and $60 million for the endowment and annual fund.

Bates’ endowment, as of last June, was $251 million, Hall said.

Bates College has about 1,800 students, and tuition, fees, room and board are $66,720 a year. In the incoming class this year, 42 percent received need-based financial aid.

Bates has been open to men and women from all racial, ethnic and religious backgrounds since its founding by Maine abolitionists in 1855.

Noel K. Gallagher can be contacted at 791-6387 or at:

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