I want to read someone's tweets from the past, but Twitter doesn't allow me to see more than 5000. How can I see them?
Previously, when you ran a search on Twitter.com or within the app, the search results prioritized tweets with high engagement (favorites and retweets), but didn’t include all tweets that might fit that search query. Now, every tweet relevant to each query will show up in results — you may just have to scroll for hours (days?) to get to it. In other words, the search functionality remains the same, the results are just more comprehensive.
Try Twitter Search: Topsy to search for public tweets of a user.
"Sort by oldest"
"All Time" or "Specific Range" from the left sidebar.
Note: Oldest tweet in their archives seems date back to 2009 only.
There is an open source project I am affiliated with called bmtu https://github.com/insom/bmtu which can let you save tweets of any account. If you have trouble making it work, let me know and I will send you some modified version of the Python source code.
snapbird.org is pretty great for that...all you have to do is sign in with your twitter account and then it'll let you pick who/what to backtrack on. -> http://snapbird.org/
you can access every tweet ever made via the library of congress, but you'll have to do more digging to find out how and where