In the Summer 2008 issue of Dttp: Documents to the People, Kris Kasianovitz has a thoughtful overview of copyright of state and local documents and how that interacts with efforts to digitize such documents.

The article:
Why Care About Copyright? by Chris Kasianovitz. Dttp, v.36, no. 2, Summer 2008, p. 12
Gives a history of state/local copyright and argues that for history's sake and on the principle of free access to government information, copyright law ought to be amended to give state and local gov't documents the same public domain status as federal documents.
The article is not yet freely available online (print copy available at UMN Libraries), but some of the history covered is also available on the government copyright page at http://freegovinfo.info/copyright
The whole Summer 2008 Dttp is well worth the read. There is also a freely available web supplement that you should check out at http://wikis.ala.org/godort/index.php/DttP_Supplements_v36_n2.
Source: FGI Blog