A statement floating around on Twitter is that "A URL is a promise". A fine sentiment, and I hope that link continues to work in the future. The Internet is not a static thing, but being able to send someone a link and have it continue to work.
I broke a promise by installing a new blogging engine and removing the older content. Links stopped working, external blog posts went nowhere, and the experience for users was generally poor.
I've tried to fix this by loading the posts into the new site. The old site was Django and this site is Ghost, so I've simply opened the sqlite3 database and copied the contents out by hand. I've made sure that the timestamps and URL slugs match, so everything works as it did.