The Trail of the Hawk by Sinclair Lewis

THE TRAIL OF THE HAWK is an early Sinclair Lewis novel, which follows the fortunes of 'Widow Ericson's boy Carl,' of Joralemon, Minnesota. Carl becomes 'Hawk' Ericson, a daring aviator, and marries a very nice girl indeed. They had promised to find new horizons for each other, and when the resources of a New York flat in the way of horizons are exhausted, they sail for South America.