Hello Tom. Welcome to Wikipedia. Thanks for your note about Centralia Massacre (Washington). It would be great if you were interested in contributing to (and correcting) the article. The interesting thing about Wikipedia is that you already have all the tools you need for editing right in front of you. On the article page you simply click on the edit button - this will bring up the text of the document, and you are able to make the changes you feel are appropriate. For more detailed instructions about editing you can follow this link to the welcome page.
To answer what I think is your real question - there is no central authority you need to contact to make your changes. For both better and worse, your edits will be reviewed by others (such as myself) who keep an eye on labour related articles. If you are comfortable with revealing some information about yourself you may want to leave a short note on the discussion page of the article (Talk:Centralia Massacre (Washington) outlining some of your changes, and perhaps more importantly, the fact that you have legitimate expertise in the subject area. Also, just as a warning, there are occasions when people who perhaps do not know a topic as well as they think they do, may alter information which you believe is correct. This may also happen for political purposes (and sometimes simply to make trouble!). I wouldn't expect this particular topic to be terribly controversial, I just wanted to mention the possibility so you know the environment you are working in.
Thanks for your interest in helping out Tom. Be careful... it always starts with just one edit, and before you know it you're addicted to Wikipedia like the rest of us! Don't hesitate to contact me if I can be of any help. Cheers. Chris.--Bookandcoffee 16:58, 15 September 2006 (UTC)