Typically of illustrated books of the period, this was sold by subscription, where subscribers would get the work in "parts" or "fascicles," which they would then pay for, allowing the author to use that money to produce the next part; this process continuing until the book was finished.
The birds in the American Ornithology were not shown in any scientific order, but essentially in the order Wilson came across them, beginning with the more common and popular birds. Wilson prepared his drawings for each bird based on his field sketches, as well as on studies he made of specimens that he had collected or which were given to him or which he found in the Peale Museum.
One point to note is that funding was more available when George Ord produced the later editions-—as the work had by then achieved a considerable reputation—-so whereas the paper used in the first edition was barely bigger than the plates themselves, the later edition prints have bigger margins. The lack of money for the first edition, compared to the later editions, also means that the paper and ink for the first edition were not as good quality and so first edition prints tend to have condition issues not found in the later edition prints.
For the coloring, Wilson started by using local artists, such as Alexander Rider (who would later be involved with Bonaparte’s supplement), but he then switched to amateur or untrained artists who would follow his directions more closely. One of these was Charles Robert Leslie, who moved to England and went on to become a famous artist there.
Click here to see more information on this print and the color printing]
If one is used to looking at the dramatic and imposing double-elephant folio prints of John James Audubon, then Wilson's small folio images might seem tame and unimpressive. However, they are really charming images, teaming with a variety of birds, their unusual appearance fascinatingly explained by the history of the work from whence they came.