Snelling was born and educated in Boston, Massachusetts. He moved to the American frontier in Minnesota and, from his late teens to his mid-20s, traded with the American Indians and explored the area. He lived with the Dakota Indians for a time and learned their language and customs. In 1828, Snelling returned to Boston and began a writing career. He wrote for New England periodicals and earned friends and enemies with his opinion pieces on American society. Over the next 20 years, he tackled subjects such as American writing, gambling, and prison conditions.