Early ornithological career

Audubon worked for a brief time as the first paid employee of the Western History Society, now known as The Museum of Natural History at The Cincinnati Museum Center. He then traveled south on the Mississippi with his gun, paintbox, and assistant Joseph Mason, who stayed with him from October 1820 to August 1822 and painted the plant life backgrounds of many of Audubon's bird studies. He was committed to find and paint all the birds of North America for eventual publication. His goal was to surpass the earlier ornithological work of poet-naturalist Alexander Wilson. Though he could not afford to buy Wilson's work, Audubon used it to guide him when he had access to a copy.

In 1818, Rafinesque visited Kentucky and the Ohio River valley to study fishes and was a guest of Audubon. In the middle of the night, Rafinesque noticed a bat in his room and thought it was a new species. He happened to grab Audubon's favourite violin in an effort to knock the bat down, resulting in the destruction of the violin. Audubon reportedly took revenge by showing drawings and describing some fictitious fishes and rodents to Rafinesque; Rafinesque gave scientific names to some of these fishes in his Ichthyologia Ohiensis.

On October 12, 1820, Audubon traveled into Mississippi, Alabama, and Florida in search of ornithological specimens. He traveled with George Lehman, a professional Swiss landscape artist. The following summer, he moved upriver to the Oakley Plantation in Feliciana Parish, Louisiana, where he taught drawing to Eliza Pirrie, the young daughter of the owners. Though low-paying, the job was ideal, as it afforded him much time to roam and paint in the woods. (The plantation has been preserved as the Audubon State Historic Site, and is located at 11788 Highway 965, between Jackson and St. Francisville.)

Audubon called his future work The Birds of America. He attempted to paint one page each day. Painting with newly discovered technique, he decided his earlier works were inferior and re-did them. He hired hunters to gather specimens for him. Audubon realized the ambitious project would take him away from his family for months at a time.

Audubon sometimes used his drawing talent to trade for goods or sell small works to raise cash. He made charcoal portraits on demand at $5 each and gave drawing lessons. In 1823, Audubon took lessons in oil painting technique from John Steen, a teacher of American landscape, and history painter Thomas Cole. Though he did not use oils much for his bird work, Audubon earned good money painting oil portraits for patrons along the Mississippi. (Audubon's account reveals that he learned oil painting in December 1822 from Jacob Stein, an itinerant portrait artist. After they had enjoyed all the portrait patronage to be expected in Natchez, Mississippi, during January–March 1823, they resolved to travel together as perambulating portrait-artists.) During this period (1822–1823), Audubon also worked as an instructor at Jefferson College in Washington, Mississippi.

Lucy became the steady breadwinner for the couple and their two young sons. Trained as a teacher, she conducted classes for children in their home. Later she was hired as a local teacher in Louisiana. She boarded with their children at the home of a wealthy plantation owner, as was often the custom of the time.

In 1824, Audubon returned to Philadelphia to seek a publisher for his bird drawings. He took oil painting lessons from Thomas Sully and met Charles Bonaparte, who admired his work and recommended he go to Europe to have his bird drawings engraved. Audubon was nominated for membership at the Academy of Natural Sciences of Philadelphia by Charles Alexandre Lesueur, Reuben Haines, and Isaiah Lukens, on July 27, 1824. Nevertheless, he was denied the support he was seeking and his nomination was subsequently rejected by vote on August 31, 1824, around the same time accusations of scientific misconduct were levied by Alexander Lawson and others.