thirtyfirst

Then our Lord was thirty years old from his nativity and thirteen days beginning of the thirtyfirst year.

The Golden Legend, vol. 3 1230-1298 1900

If then, by the future treaty of peace, Spain preserves West Florida, she alone will be the proprietor of the course of the Mississippi from the thirtyfirst degree of latitude to the mouth of this river.

The Diplomatic Correspondence of the American Revolution, Vol. VIII Jared Sparks 1827

She cannot, therefore, pass beyond the Natchez, situated towards the thirtyfirst degree of latitude; her rights are, therefore, confined to this degree; what is beyond, is either independent or belonging to England; neither Spain nor the Americans can have any pretensions thereto.

The Diplomatic Correspondence of the American Revolution, Vol. VIII Jared Sparks 1827

North America, he asked me what were our boundaries; I told him that the boundary between us and the Spanish dominions was a line drawn from the head of Mississippi, down the middle thereof to the thirtyfirst degree of north latitude, and from thence by the line between Florida and Georgia.

The Diplomatic Correspondence of the American Revolution, Vol. VIII Jared Sparks 1827