Who said "Don't watch the clock; do what it does. Keep going."?

This quote is attributed to Charles Crocker.

Don't watch the clock; do what it does. Keep going. - Charles Crocker

"Don't watch the clock; do what it does. Keep going."

Charles Crocker Perseverance

Railroad Tycoon American 1822–1888

"The best time to plant a tree was 20 years ago. The second best time is now."

"Success is not final, failure is not fatal: it is the courage to continue that counts."

"The only way to do great work is to love what you do."

"Life is what happens when you're busy making other plans."

"Perseverance is the key to success."

"Don't give up on what you believe in."

"I've been through worse."

"You learn to live with the pain."