In 1825, after graduating from Harvard Medical School, Dr. Howe participated in the Greek war for independence. He also wrote a sketch of the Greek revolution. Because he was then seeking a new profession, he visited places in Europe in order to learn how to educate blind children. He taught Laura Bridgman—who had been blind and deaf since age two—how to communicate. The Perkins School for the Blind, a pioneer institution in the United States which he founded, was awarded both private and government funding, and his action also led to public education and improved treatments for mentally defective children.

He and his wife, Julia Ward Howe, jointly edited an antislavery paper, and she wrote the Civil War "Battle Hymn of the Republic."