My Change History tool launched to show three months of account changes

A new My Change History tool on the AdWords Tools page listed the changes made to an account over the previous three months, so advertisers could see when a bid, campaign or targeting setting had been altered. Accounts with several logins could use it to see which user made each change.

The Screaming Frog timeline dates this to September 8, 2005; the Inside AdWords post is dated September 9.