Like a few other people here, I read Go Down Together, and can't recommend it highly enough.
I noticed all the way through it that the author scrupulously refers to the couple as Clyde and Bonnie, then explains right at the end that they were never referred to as Bonnie and Clyde until this movie in 1967.
[deleted]
[deleted]
[deleted]
What about this newsreel footage where the announcer refers to them several times collectively as 'Bonnie and Clyde'?
http://www.youtube.com/watch?v=BpFWTEFvcBY
.
Another newsreel in which the announcer refers to them as 'Bonnie & Clyde':
https://www.youtube.com/watch?v=Wl9lchv2L2U&t=17s
.
A newspaper clipping from June 1934 (a month after their deaths) that advertises the aftermath footage, refers to them as 'Bonnie and Clyde':
http://texashideout.tripod.com/howell.jpg
Jeff Guinn's otherwise well-researched book is wrong that they were not known as 'Bonnie and Clyde' until after the landmark 1967 film. All the film did was reinvigorate new interest in the pair. By the 1960s they were largely forgotten, but thanks to the movie's commercial success -- which sparked off numerous songs and books that continues to today -- public interest in them has not abated ever since.
.
Obituary of Bob Alcorn, one of the posse who shot down B&C:
http://texashideout.tripod.com/alcorn_5_24_64.jpg
Coincidentally, he died 30 years to the day after the ambush (May 23, 1964). Anyway, my point is that the article calls them 'Bonnie and Clyde,' and this was three years before the film was released, so, once again, no, the movie didn't christen them Bonnie and Clyde.
.
Article written the day after their deaths, where they're referred to as 'Bonnie and Clyde' (second paragraph):
http://1.bp.blogspot.com/_FfetiF7C9vo/SL6bmeSbXtI/AAAAAAAAKyk/3nDVp4azdxY/S600/unruffled.jpg
.