Columbus. That's why it's called "pre-Columbian" which means "before Columbus.
Precolumbian means before Columbus arrived in the Americas.
Improvement Era ended in 1970.
It ended about 65 million years ago
The Cenozoic era started 65 million years ago.
The period of time prior to discovery of the Americas by Christopher Columbus (i.e.: before 1492).
Era of good feelings
At the Threshold of an Era ended on 1999-12-18.
The Mesozoic era began roughly 250 million years ago, and ended 65 million years ago. (This Era ended because of the K.T. extinction)
The Mesozoic era ended with a massive impact caused by an asteroid hitting Earth, leading to the extinction of the dinosaurs.
Diaz
I believe it was 1877
Andy Pettitte ended his career with a 3.88 ERA.