Abert was born in Shepherdstown, Virginia (now West Virginia; also disputed to be Frederick, Maryland) to John Abert and Margarita Meng, his father being said to have emigrated to the States as a soldier with Jean-Baptiste Donatien de Vimeur, comte de Rochambeau in 1780.

Abert volunteered as a private in the District of Columbia Militia for the defense of Washington in 1814, and was brevetted Major, Staff Topographical Engineer, for gallantry at the Battle of Bladensburg, Maryland, August 24, 1814.

In 1818, the US War Department created the Topographic Bureau as part of the Corps of Engineers, under the command of Major Isaac Roberdeau.

The geographical and other information concerning this continent which its officers have collected and published has challenged the admiration of the scientific world, while the practical benefit of their labors has been felt in nearly every State and every Territory; the whole forming a proud monument to him who was its founder.

As a citizen and a man, Colonel Abert was remarkable for the steadfastness of his friendships, for his candor and unostentatious hospitality.

Equally unostentatious, but no less sincere, was the simple piety which supported his declining years, and left behind an example which the proudest soldier would not be ashamed to follow.