Who said "An empire requires constant attention and vigilance."?

This quote is attributed to Cornelius Vanderbilt.

An empire requires constant attention and vigilance. - Cornelius Vanderbilt

"An empire requires constant attention and vigilance."

Cornelius Vanderbilt Work

Shipping & Railroad American 1794–1877

"I have always believed that the best way to earn money is to first learn how to make it."

"The public be damned."

"Concentrate your energy, thoughts, and capital."

"I have made my money by the blood, sweat, and tears of the American working man."

"Hard work never killed anybody."

"Work with purpose and integrity."

"Hard work pays off in the end."

"A man's gotta do what a man's gotta do."