Succeed at vs succeed in [American English]

Succeed in seems by far the more common in both AmE and BrE.

Some stats from the British National Corpus and the Corpus of Contemporary American English:

When followed by a gerund-participial, COCA has both, but the BNC returns no results:

This suggests that at may be less acceptable when there is a gerund-participial complement in BrE.

When followed by a noun phrase, the balance still tilts heavily in favor of in for both the BNC and COCA, however it's dubious whether these prepositional phrases are really complements of succeed as they often denote domains or physical locations more so than actions.