The phrase belongs to President Theodore Roosevelt, who, while visiting Andrew Jackson’s home, the Hermitage, in Nashville, Tennessee, drank a cup of Maxwell House coffee and was offered a refill.
He is said to have replied, “Will I have another? Delighted! It’s good to the last drop!”
By the way, there actually was a Maxwell House.
A luxury hotel in Nashville, Maxwell House was the place where, in the 1880s, the coffee was first served.