Unfortunately most archive sites are behind paywalls. Some are economical - you can search all the stories and back issues you want for a certain amount of time for a set price. The Boston Globe archives work this way. Others are a set price for a certain number of articles, so you have to pick and chose carefully, and still others only offer stories written by their staffs (no TV listings, no AP stories). Newspapers as they have been known for 150 years or so are under attack and have to find new sources of revenue, and this is one way of bringing money in.