The town gets its name from Ernst Gruene, who settled in the area in 1845. Today, the town is still mostly populated by descendants of German immigrants. The German pronunciation of "Gruene" is "groon," but over time the town's name has become anglicized to "green." There are several theories about how this happened, but the most likely explanation is that English speakers simply found it easier to pronounce "green" than "groon." Whatever the reason, the town's name is now firmly entrenched in the English language.