[5] He studied law, was admitted to the bar in 1826 and commenced practice in Bayou Sara, Louisiana.

[5] In 1838, he won election to the Louisiana State Senate from Catahoula, Ouachita and Union Parishes, and he was reelected in 1842.

[9][10] A longtime member of the Louisiana Militia, in 1842 Downs was appointed brigadier general of the organization's 6th Division.

[13] When Van Buren came out against annexing Texas, Downs resigned, but he agreed to run again after James K. Polk was nominated.

[13] In the Senate, Downs was an unusually staunch supporter of the institution of slavery, from which he personally profited.

"I call upon the opponents of Slavery to prove that the white laborers of the North are as happy, as contented, or as comfortable as the slaves of the South," he said in one speech.

"[14] After his term, he was appointed by President Franklin Pierce as United States Collector of Customs for the District of Orleans in 1853 and he served until his death.