The University of Southern Maine has received what it describes as the largest gift in its history — mostly in the form of maps. Loosely valued at $100 million, Harold Osher of Portland is giving 450,000 maps to the Osher Map Library at USM, including a 1475 map of the Holy Land and the first modern printed map.

In addition to the maps, Osher, 94, is giving USM an undisclosed amount of cash to supplement an existing $3 million endowment for the library that he previously funded.

University President Glenn Cummings announced the gift Friday morning.

“I am very honored to accept this vote of confidence on the part of the Osher family, and we pledge to be excellent partners and stewards of the collection,” Cummings said. “They are fulfilling their family’s vision of a major collection at the university, here in their favorite city. That feels great.” 

The gift will bolster the profile of the library on USM’s Portland campus and allow the university to hire a full-time executive director and fund it with other resources necessary to transform the library into a fully functioning and accessible cultural resource for Portland and Maine and the science of cartography around the world, Cummings said.

Osher family spokesman Glenn Parkinson pegged the monetary value of the map collection at $100 million but said that figure represents an estimate and isn’t the most important aspect of the gift.

“The scale of this collection is what’s impressive — 450,000 maps. That’s a half-million maps. That a big number,” Parkinson said. “The monetary value is really impossible to state. Some are rare or are one-of-kind. How do you price a rare map that was traded 20 years ago? One hundred million dollars is as good a number you could come up with. I have heard also $200 million.”

The Oshers donated their initial collection of historic maps, charts and documents to USM in 1989. Five years later, the university opened the Osher Map Library and Smith Center for Cartographic Education. In 2009, expanded facilities opened at Bedford Street and Forest Avenue on the Portland campus, its existing home.

Friday’s gift, Parkinson said, caps the Oshers’ effort to build a world-class map library in Portland. “They have worked for decades to build a library of distinction, a significant map library. More important than that, they see maps as powerful educational tools. That is the heart of what they want. They could have put this collection in a library anywhere, and they wanted it in a public institution in Maine,” he said.

Osher, a retired cardiologist, has added to the collection with additional purchases annually. Peggy Osher died in May. Parkinson said the timing of the gift was coincidental to Peggy Osher’s death. “This has been in the works for a long time, and unfortunately she died just before the resolution,” Parkinson said.

The Oshers are longtime benefactors of the arts, and their support often involves gifts of art they’ve collected. The Oshers also collected prints and graphics by Winslow Homer and donated several hundred pieces to the Portland Museum of Art.

Parkinson said the maps are important educational tools because they reveal the history of cultures across the globe in a universal, visual language.

“Harold will tell you they are powerful educational tools,” Parkinson said. “He will go on to say that maps involve all areas of human activity, not just geography, not just political, not just religion. Every area of human activity is eventually portrayed. He wants the maps used by arts students, math students, history students, religion students. Maps tell all these wonderful stories.”

Cummings described the gift as “a transformative partnership. It’s one of the most significant collections in the country, and it is the largest gift in USM history and potentially in UMaine system history. We’ve never had a gift of that size or value.”

Among other items, the collection includes a series of rare early maps of the northern Maine border with Canada and maps of North America as the continent was first mapped by Europeans.

Globes and maps on display at the University of Southern Maine library in Portland. (Portland Press Herald file photo)