I ran across a story that used "an historic" and gathered other evidence to show how pervasive this error is in print. This post is about why the article should be "a," not "an." I’ll save the "historic" vs. "historical" issue for another post.
The rule in English is "Use a before a consonant sound; use an before a vowel sound." That is about as straightforward as rules of English get. But the letter h gives people fits, apparently.
This article was originally posted by the Raleigh News & Observer, a subsidiary of The McClatchy Co.; is posted here to provide continuity; and is copyright © 2011 The News & Observer Publishing Company, which reserves the right to remove this post.