why did 29inches get chosen as a wheel size?

when 700cc existed already, how com 700 diameter wheels didnt just get "beefed up"??
i must say i know nothing of the history of 29 er's so this may be really
obvious.

700c and 29ers are the same size. The term 29er is just an mtbing thing and I guess differentiates road and mtb rims of the same size though the road ones seem to stand up to most mtbing just fine

29er is a beefed up 700cc

29 with tyres on roughly not really 29inch rims

[Edit]Clubber Beat me by a second, Dam it! :D[Edit]