“During the years after the  fire, Reinhardt was rehabilitating and experimenting on the guitar that his brother had given him. After having played a broad spectrum of music, he was introduced to American jazz by an acquaintance, Émile Savitry, whose record collection included such musical luminaries as Louis Armstrong, Duke Ellington, and Joe Venuti and Eddie Lang…
There is a long history to the jazz violin. Chris Haigh’s website does a great job of documenting this lineage. Moreover, there are excellent contemporary jazz violinists. More interesting than thinking about this history in terms of a continuing linear evolution is considering the breaks and ruptures, and the roads not taken. On this latter note, there was a noticeable shift after the 1920s in which it seems that the (sometimes prominently featured) string quartets and (frequently prominently featured) violinists of hot jazz bands all but disappeared. By the time of big bands and the swing era in the 1930s, strings were no longer commonplace in popular jazz.
I think there were perhaps multiple factors that played into this transformation, and there are no simple reasons for the change. For example, a pat explanation is that big bands were simply too loud for violins and cellos. While at first glance this makes sense, it overlooks the important story of Eddie Lang, often credited with being the first jazz electric guitarist. The story with Lang is that he experimented in the early 20s with some of the first valve-based amplifiers made by RCA, using pickups made from hacked phonograph cartridges and telephone receivers. Already as early as 1917, the Russian scientist and cellist Lev Theremin had designed an electric cello, built by the early 20s, and presumably jazz string players experimented with methods of amplification just like guitarists.
Here are some related pictures:
The violin has a long history in American folk music.
Buskers in the early 1930s
New Orleans band from early teens featuring acoustic guitar, violin, bass.
Somehow the French gypsy jazz guitar/violin duo of the thirties and forties has eclipsed its Italian-American forebear which dominated the jazz age in the twenties. Django and Grappelli were standing on the shoulders of giants, it turns out. Where Grappelli plays like fancy stitching around the top edge of the rhythmic pocket, Joe Venuti is deep inside it, driving forward with confidently virtuosic technique.
Django was obviously a remarkable musician, but Eddie Lang is the “father of jazz guitar”. These two blues guitar duets with Lonnie Johnson (incidentally Johnson was a Chicago-based multi-instrumentalist and signer, and is credited with being the first to play an electric violin) seem to be at the same time textbook examples of the blues and also feature some exploratory reharmonizations that point towards things to come.
One more: “Blue Blues” by the Mound City (St. Louis) Blue Blowers, recorded in 1924. It features Eddie Lang on guitar and kazoo and comb (played with tissue paper). So good!