Someone - I think a professor of a class I once took - mentioned that starlings were introduced into North America because a Shakespeare fancier believed that all birds mentioned by the Bard should be represented on these shores.

The person was trustworthy, so I never bothered to chase down the actual evidence. But a bit of random surfing landed me on a site that verifies that it is true; the person in question was apparently a drug manufacturer: Introduction of Starlings. (Another site with more detail is here. Though I'm not sure I condone that web-siter's plan to take "Americanized" starlings back and re-release them in Britain; that could cause a variety of problems from disease transmission to weird genetic combinations. Though it's also possible that the plan is an elaborate put-on; I can't quite tell.)

The name of the man to blame for starlings being here is Eugene Schieffelin. Though that site says that the Shakespeare connection is "probably not true" (darn). However, they do verify this:  that the so-called House Sparrow was introduced under similar circumstances (it is a different family from most common North American sparrows: it's a Passeridae and they are Emberizidae (though on a higher taxonomic level, they are both considered "passerine" birds). I've actually been told the house sparrow is more closely related to the finches than it is to the "true" wild sparrows.)

Interestingly, apparently both the sparrow and the starling are on the decline in the UK, whereas they are considered pests here (most people blame starlings for the decline of bluebirds: they have similar nesting requirements and the starlings are more aggressive, so they get the nest cavities.)