Twitter only lets you see a portion of your tweet history, but there's an easy way to get a copy of everything.You can request to download your Twitter archive, which contains a searchable collection of every tweet and retweet you've ever made since first making your account.
Here's how to request your own free Twitter archive.
Step 1 :Go to your account settings by clicking on the profile icon at the top right of the page and selecting Settings from the drop-down menu.
Step 2 :Click Request your archive.
Step 3: When your download is ready, Twitter will send an email with a download link to the confirmed email address associated with your Twitter account.
Step 5: Once you receive the email, click the Go now button to download a .zip file of your Twitter archive.
Step 6: Unzip the file and click index.html to view your archive in the browser of your choice.
Ref : Twitter Blog
