There are any number of sources for researching the Koreshans, Cyrus Teed and others. Some of these online databases charge for access, but there are a good number of sources that are free to use.
I recently ran across a couple of places where you can search for old newspaper articles. The first is the Library of Congress which has a section called Chronicling America. This section of the Library’s site covers the years 1860-1922, and includes papers from about half the states, including California, District of Columbia, Florida, Kentucky, Minnesota, Nebraska, New York, Texas, Utah, and Virginia.
Another web site, which may not have caught the eye of many people is a site called Old Fulton New York Post Cards. Post cards? Well, they are much more than post cards. This site has an extensive collection of newspapers. Their site invites you to search from over 15,377,000 New York newspaper pages! The site can sometimes be a little slow loading pages, but it is well worth it.
Our own collection of material at the Koreshan State Historic Site is available online. It is updated about twice a year and will be updated soon.