Chicago, Burlington and Quincy Railroad Co. Issued to and Signed by Nathaniel Currier - Autograph

In 1835, Currier started his own lithographic business as an eponymous sole proprietorship. He initially engaged in standard lithographic business of printing sheet music, letterheads, handbills, etc. 

However, he soon took his work in a new direction, creating pictures of current events. In late 1835, he issued a print illustrating a recent fire in New York. Ruins of the Merchant's Exchange N.Y. after the Destructive Conflagration of Decbr 16 & 17, 1835 was published by the New York Sun, just four days after the fire, and was an early example of illustrated news. In 1840, Currier began to move away from job printing and into independent print publishing. In that year, the Sun published his print Awful Conflagration of the Steam Boat 'Lexington' in Long Island Sound on Monday Eveg Jany 13th 1840, by Which Melancholy Occurrence Over 100 Persons Perished, another documentation of a news event, three days after the disaster; the print sold thousands of copies.

In 1850, James Ives came to work for Currier's firm as bookkeeper. Ives' skills as a businessman and marketer contributed significantly to the growth of the company; in 1857 he was made a full partner, and the company became known as Currier & Ives. 

Currier & Ives are best known as creators of popular art prints, such as Christmas scenes, landscapes, or depictions of Victorian urban sophistication; however, the firm also produced political cartoons and banners, significant historical scenes, and further illustrations of current events. Over the decades, the firm created roughly 7,500 images.

Currier retired from his firm in 1880, and turned the business over to his son Edward. Further info at en.wikipedia.org