In her books, she integrated global historical events into the telling of a person's life. Her purpose was to make historical figures "alive for children". For example, her first historical book, "George Washington's World", showed how the French Revolution, American Revolution, and British imperialism were intertwined and affected Washington's life. During her career she wrote 19 nonfiction children's books. Foster traveled extensively and most of her books were translated into 12–15 languages and were distributed by the U. S. State Department. Foster died in Westport, Connecticut. Her papers are held at the University of Oregon Libraries, Special Collections & University Archives; and University of Minnesota Library, the Children's Literature Research Collections. Many of her books are still in print and some are used as textbooks, particularly in the homeschooling market. Her daughter, Joanna, worked as an editor of children's books and wrote two youth books of her own, "Pete's Puddle" (1950) and "Dogs Working for People" (1972). NH: Four children's books by Eaton were among the annual Newbery Medal runners-up, now called Newbery Honor Books.