Liberty and Union Now and Forever, One and Inseparable
The motto of Dakota Territory was Liberty and Union, One and Inseparable, Now and Forever. This language was suggested by Dr. Joseph Ward of Yankton, South Dakota, who was quoting from Daniel Webster's Reply to Hayne. However, the motto used for the Territory had two of the phrases reversed; when North Dakota became a state that error was corrected.
[North Dakota Constitution Article XI, Section 2]
Serit ut alteri saeclo prosit
This translates from Latin as "One sows for the benefit of another age". A group of Fargo high school Latin students lobbied for the motto.
[North Dakota Century Code 54-02]