Reader Ingrid Hansmann wishes to go back in time. She writes:
I visited a web page about a year ago that had some information that I wanted. I’ve since returned and the page has changed. Is there any way I can see the old version?
There is. Google caches many webpages and there’s a chance that an old version of the page you’re looking for is available in cached form. Just use this formula:
Enter http://webcache.googleusercontent.com/search?q=cache:
and then paste in the full address of the page you want to visit. For example, if I wanted the cache from http://www.example.com/fuzzybears
I’d enter this into my browser’s address field:
http://webcache.googleusercontent.com/search?q=cache:http://www.example.com/fuzzybears
The result would be the version of the page that was last crawled by Google.

If Googe cachew fails, try the Wayback Machine.
But suppose the page is getting on in years, has been subsequently crawled, and lost the content you wanted to see. You have another option in the form of the Internet Archive Wayback Machine. As its name implies, the Wayback Machine lets you search waaaay back. In some cases you might turn up multiple instances of a page. Hopefully one of those instances includes the content you’re after.