In 1850, Cauldwell bought out Elbridge G. Paige's one-third ownership stake in the Sunday Mercury for $1,200. Cauldwell expanded the paper and increased its coverage of literature, city news, and sports. Sylvester Southworth and Horace P. Whitney (1834- August 24, 1884) soon joined Cauldwell, and the paper prospered.
Cauldwell and the Mercury are credited as being the first newspaper to regularly