The Internet Archive's Wayback Machine can help you view previous versions of websites. This can be particularly helpful for admin law research, when agency webpages are dynamic and you need to find the text displayed at a certain point in the past.
Sometimes, you need to find news coverage about an event, case, or law in the past. Historical newspapers are a useful starting place.
More historic newspapers can be found through Snell's database list and through the Boston Public Library's guide.
The Northeastern University Archives and Special Collections is a useful resource for historical news, particularly about Northeastern history and newsletters of community groups.