A historic or an historic?


A historic is more common in both American and British English, but both usages are sufficiently common to be considered correct.





Google's N-gram viewer allows us to see how this usage has changed over time. Here's the use of "a historic" and "an historic" for US English over the last century:

'a historic' versus 'an historic'

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It's clear that American English has shown a strong preference for "a historic" since the forties.

Here's the chart for British English:

'a historic' versus 'an historic'

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British English also shows a preference for "a historic", although not as strong. This preference is also more recent, perhaps reflecting the influence of American English brought about by the Internet.