Author Howard wanted coauthor Ada to push his wheelchair on the sunny side of the street. They wrote it in 1899. First published in 1903, the year composer Entwisle died.
The Carters knew this song through their uncle Laish. Not to be confused with the Keep On The Sunny Side written by Jack Drislane/Theodore F Morse and recorded in 1906 by both Billy Murray and Byron Harlan.