Born in New York City in 1883, Gladwin worked in the city as a stockbroker from 1908 to 1922, his first successful career. However, in 1922 he decided to move west to California, and there he began work at the Santa Barbara Museum of Natural History, taking a special interest in the mutations of butterflies.
Gladwin, born in New York City in 1883, initially pursued a successful career as a stockbroker in the city from 1908 to 1922.  In 1922, he moved west to California and began working at the Santa Barbara Museum of Natural History, focusing on butterfly mutations.