US Aerospace Company Mergers

I saw once a tree chart showing all of the aircraft companies that existed in 1920 or so and how they have merged with other companies or been bought out ect. Has anyone else seen anything like that or know where to get it?

Edit:
It might have been early to mid 30's

[edit on 3/15/2005 by SwitchbladeNGC]

Originally posted by SwitchbladeNGC
I saw once a tree chart showing all of the aircraft companies that existed in 1920 or so and how they have merged with other companies or been bought out ect. Has anyone else seen anything like that or know where to get it?

I thought there was one a few years back in AWST, but not back to 1920. I do not keep old issues, so you may want to ask them.

Afraid I don't know that one, I have a book that shows how the UK went from having 27 Aircaft makers in 1947 to just one by 1977 (can anyone here name all 27?) but nothing similar on the US industry.