Lot-et-Garonne was formed during the French Revolution on 4 March 1790 with parts of the old provinces of
Gascony. It was divided into nine districts: Agen, Nérac, Marmande, Tonneins, Villeneuve, Lauzun, Monflanquin, Casteljaloux and Valence. 
Aiguillon were alternatively the capital of the department but in 1791 it was decided that only Agen would be the capital.
Several of the original southeastern cantons in the arrondissements of Agen and Villeneuve-sur-Lot were separated from it in 1808 to become a part of the newly created department of Tarn-et-Garonne.