Unfortunately there isn't an easy way to do this.
Also, keep in mind that once stuff is posted publicly to the interweb, it's often copied to other locations all over the web. For example, Google keeps a copy / cache of almost all the images and text posted to BYC.
... and then there's this:
https://archive.org/
BYC 18 years ago: https://web.archive.org/web/20000619214139/http://www.backyardchickens.com:80/
Also, keep in mind that once stuff is posted publicly to the interweb, it's often copied to other locations all over the web. For example, Google keeps a copy / cache of almost all the images and text posted to BYC.
... and then there's this:
https://archive.org/
BYC 18 years ago: https://web.archive.org/web/20000619214139/http://www.backyardchickens.com:80/