Principia was started by an international couple, Mary Kimball Morgan being an American by birth, and her husband, William Edgar Morgan of Welsh descent, born in England. In the school's second year, 1899, a boarding department was established for five students, one of whom was "A boy from Australia, whose parents simply notified the school, after the boy had set sail, that he was on his way to America to enter Principia." ( Edwin S. Leonard, As the Sowing, p.62)

International students continued to find their way to Principia over the next 25 years. Then, with the founding of Principia's School of Nations, a scholarship program was established to enable more international students to enroll. A woman from Germany received the first such scholarship in 1927. By 1930 two more German students were on campus, as well as students from Ireland, Peru, Belgium, Japan, and Canada. Seven children were sent to Principia from England for the duration of World War II.

A gradual increase continued until the 1970s, when a national awakening of our global interdependence occurred, and scholarship funds greatly increased. Over the next 20 years students arrived from 57 different countries.

Currently nearly 70 students from Africa, Asia, Europe, Latin America, Oceania, and Australia attend the college, enabling us all to celebrate the beauty of diversity.