What is it? A sprawling Western, following a daredevil and his more demure wife as they move to the edge of the newly opened-for-settlement Oklahoma territory in 1889, through to 1930 itself.
Why did it win? If there's one genre that challenges the War movie for prominence at the Oscars, it's the sprawling Western - so really here we're seeing another tradition born. And we're also seeing, even this early, Oscar's love of cries for tolerance and understanding between races and cultures.
Did it deserve to win? It's hard to judge a film so dated nowadays, what with its casual racism and rather broad acting, but then it wasn't a vintage year. Cimarron was up against East Lynne (melodrama even by 1930's standards), Skippy (kid's film), Trader Horn (African-set adventure) and The Front Page. The latter's the only one whose reputation still survives, largely down to its remake as the superior His Girl Friday.
Worth a look? Only if you're a real Best Picture die-hard.