After a 1966 sellout solo exhibition at the Abercrombie & Fitch Gallery in Chicago, Sloan left Lincoln Park to embark upon a lifetime of capturing the world's rainforests in paint.
He was the first wildlife artist in North America to turn all his efforts as a painter to documenting exotic animals of the world's tropics.
He first traveled to British Guiana (Guyana) in 1969 and made seventeen expeditions to the Amazon Basin, the Peruvian Andes, Guatemala, Trinidad and Tobago, Belize, Mexico's Yucatán Peninsula and Thailand.
In March 2002 at the invitational, juried exhibition Impressions Of Bonnet House in Ft. Lauderdale, Florida, he was given the Peoples Choice Award.
He has been commissioned by the World Wildlife Fund to design postage stamps and first day covers for Trinidad, Tobago, Guatemala, the Philippines and the Falkland Islands.