The State Motto of Idaho is the Latin phrase “Esto Perpetua,” which means “Let it be Perpetual.” Idaho State Motto is appeared on the state quarter, the great seal and Idaho’s state flag. The motto “Esto Perpetua” was incorporated in the Great Seal of the State of Idaho designed by Emma Edwards Green in 1890/91 and adopted by the first Idaho State Legislature on March 14, 1891. Idaho has never adopted an official Idaho State Motto. Instead, the motto Esto Perpetua was accepted as an element of the adopted state seal.
The Idaho State Motto has its roots in a sentence made by Pietro Sarpi (1522-1623) a Venetian theologian and mathematician. His last words before he died were: “Esto perpetual”, meaning: “Mayest thou (Venice) endures forever”. This State Motto of Idaho is attributed to Venetian theologian and mathematician Pietro Sarpi (1552-1623) who, in 1623, applied it to the Republic of Venice. State Motto “Esto Perpetua”, meaning (Mayest thou endure forever!), is, according to W. Francis H. King in his Classical and Foreign Quotations (J. Whitacker and Sons, Ltd., London, 1904, p. 90), supposed dying apostrophe of Pietro Sarpi (Fra Paolo) in speaking of his beloved Venice.
This Idaho State Motto was chosen by the Grange in 1867 and by the state of Idaho in 1891. The State Motto of Idaho, Esto Perpetua was adopted by the National Grange of the Patrons of Husbandry, a farm organization constituted in Washington, D.C. on December 4, 1867. The words also appear in the closing words of Jefferson Davis’ History of the Confederacy (1881). It’s thought that the motto’s use on the Great Seal of Idaho may have been inspired by one of these sources.