According to Wikipedia: "Lucy Fitch Perkins (12 July 1865 - 18 March 1937) was an American children's book author and illustrator, famous for writing the Twins series of books. Lucy Fitch was born in Maples, Indiana, the daughter of a factory owner and businessman. She studied at the Fine Arts School in Boston, and later taught art at the Pratt Institute in Brooklyn. She worked for a time as an illustrator with the Louis Prang & Company. She married architect Dwight Perkins in 1891; they lived for many years in Chicago. The Twins books featured stories on twin siblings from different nations or different periods in American history. Twenty-six volumes of the series appeared over two decades, from the 1910s through the 1930s: The Dutch Twins, The Japanese Twins, The Eskimo Twins, The Puritan Twins, The American Twins of the Revolution, etc."