Brothers James and John Harper set up a small printing business in New York City in 1817, and then, joined by younger brothers Joseph Wesley and Fletcher, became the largest book publisher in America by 1825 under the name Harper's & Brothers. Their business survives to this day as publishing giant Harper-Collins.
In 1850 the brothers started Harper's Monthly magazine. After innovations in printing images emerged via the London Illustrated News the decade before, Harper's followed on the heels of ex-London Illustrated News engraver Frank Leslie and his Frank Leslie's Illustrated News by starting a weekly illustrated publication of their own they called Harper's Weekly in 1857.
Of course, being an important publication, Harper's covered all the major events and issues of the day. In the years leading to the Civil War Harper's kept a moderate stance on the divisive issue of slavery and strove to not alienate its Southern subscribers and readers. After the war came though, Harper's went all in for Lincoln and the Union. After the Civil War ended, Reconstruction was covered thoroughly by Harper's, and during this era Thomas Nast's illustrations made events come alive for readers. Nast's cartoons were credited for changing the public's impressions on everything from race relations to "Boss" Tweed's New York City Tammany ring. Harper's continued publishing their weekly editions until 1916.
We are fortunate to now have much of Harper's Weekly available and searchable online. The cartoons of Nast provide valuable lessons for students of history of all ages, but as the sites warn, the language of the nineteenth century is not always the racially sensitive and politically correct print we experience today. In addition to the main Harper's Weekly site, they also have an excellent black history site.
To browse and learn, check out both sites