Ukuleles: Everyone's playing them. Ads from the great uke craze of the 1910s-20s.

1917 ad.

Here’s a larger size.

University of Hawaii at Manoa has a whole Flickr set of vintage ukulele advertisements from the first decade of the 20th century:

Ukulele was all the rage on the mainland United States in the late 1910s and early 1920s. George E. K. Awai and his Royal Hawaiian Quartet popularized the small, guitar-like instrument when they performed at the Panama Pacific International Exposition at San Francisco in 1915.

During the ukulele craze, ukulele advertisements appeared in U.S. mainland newspapers.

1915 ad.