The collection was discovered at home in Pennsylvania before going under the hammer at Heritage Auctions.
An incredibly rare poster for 1931's Dracula sold for £143,000 (£89,00) - only four copies are known to exist, while a poster for 1931 western Cimarron was expected to sell for $12,000 (7,500), but ended up fetching $101,000 (£63,000).
A poster for James Cagney's classic gangster film The Public Enemy sold for $59,000 (£36,000) and Edward G. Robinson's Little Caesar fetched $41,000 (£25,000).
Director of the auction, Grey Smith, said before the sale, "These posters are among the rarest, most sought after 'Holy Grail' pieces. The Public Enemy one sheet picturing James Cagney and Jean Harlow is particularly stunning and has never been offered at auction and the Little Caesar one sheet is one of only two known copies, making this a potentially once-in-a-lifetime opportunity for the right collector."
Posters from this cinema era remain rare as most movie houses either threw the sheets away or plastered another release on top.