Dan Cody is essentially the man who made James Gatz become Jay Gatsby. After dropping out of college, Gatsby returned to Lake Superior, where he had grown up. While lounging on the beach one day, he met Dan Cody and his yacht.
Description of Cody hints of criminal activity, so Cody may have inspired Gatsby's bootleg business as well. This may have also been because although Cody left Gatsby $25,000 when he died, Gatsby never got any of it. Thus, with no resources and only a new name, Gatsby turned to crime to make his fortune for Daisy.Dan Cody was an enormously wealthy old man, a millionaire many times over, who had earned his fortune mining silver.
Dan Cody is largely responsible for who Jay Gatsby ended up becoming. If it wasnt for Dan Cody Jay would have stood a poor man only longing for Daisy. With Dan Cody's help Jay turned into a wealthy man and got Daisy back for a period of time.