Author-illustrator Ashley Bryan warmed up his audience by having them chant poems by the American poet Langston Hughes.

Then he talked about what he hoped they would take away from his new children’s book, “Freedom Over Me,” in which he imagines the lives of 11 slaves in the early 19th century.

“My hope was the spirit of these 11 would give the reader a stronger sense” of slavery, Bryan said.

By the end of his hourlong talk Saturday at the Portland Public Library, the audience of about 200 rose to their feet to give him a standing ovation.

Bryan’s rare appearance in Portland kicked off a series of talks organized by the Illustration Institute, a Portland arts group focused on the art of illustration, in conjunction with the exhibit “Picture This: The Art and Workings of the Illustration Institute,” a show of 18 illustrators on view at the library through Dec. 17.

Bryan, 93, based his newest book on an 1828 bill of sale he bought at a Maine auction more than a decade ago. The document listed 11 slaves only by first name and price along with other items being sold off from a Southern plantation.

Bryan imagined them as characters and wrote a book profiling their lives and dreams. He based their portraits on the faces of his family and friends. He imagines one as a carpenter, another as a cook, for example, and has them tell the story of how they came to the plantation and what they dreamed of doing if they were free.

It was one of six books nominated for the Kirkus Young Readers’ Literature award from a field of 500 candidates.

A native New Yorker, Bryan attended the Skowhegan School of Painting and Sculpture in the late 1940s and has lived year-round on Little Cranberry Island since retiring from Dartmouth College in the 1980s. He has written more than 50 children’s books.

The audience Saturday was filled with fans. About 15 percent had made the trek down from the Cranberry Islands, said Chris Wriggins of Yarmouth, who designed the Ashley Bryan Story Telling Pavilion on Little Cranberry Island. It houses Bryan’s puppets made from found objects and stained glass fashioned from sea glass.

“He has touched a lot of people’s lives in many amazing ways,” Wriggins said.

Abby Morrow, a children’s librarian in Ellsworth, said she had to make the drive down.

“He is the best example of a Maine author-illustrator. He celebrates creation,” Morrow said.

Writer Paulette Oboyski of Brunswick was there to hand-deliver Bryan some copies of Maine Seniors magazine, which contained her profile of him. She wanted to tell Bryan, a World War II veteran, about Honor Flight Maine, an organization that flies veterans to Washington, D.C., for a tour of the capital.

Oboyski said she will never forget her visit to Bryan’s home.

“He percolated coffee for us and made us raisin toast,” she said.

Bryan’s talk was also sponsored by the Ashley Bryan Center in Islesford, Maine College of Art, the Abyssinian Meeting House in Portland, First Book and Sherman’s bookstore.