The white crowd soon realized that Crowe was not just doodling, and rose up to kick him out. “The people rushed on him savagely and obliged him to quit,” Crowe’s traveling companion, the novelist William Makepeace Thackeray, wrote to a friend.

“Slaves Waiting for Sale,” Crowe’s 1861 painting based on the sketches, is suggestive of terrible suffering, as the mothers gaze fondly at their children for perhaps the last time. But unlike his abolitionist colleagues’ equally accurate depictions of torture, his tableau was wholesome enough to be widely exhibited. British critics at the time wrote that it aroused sympathy “without being too painful,” the art historian Maurie D. McInnis points out in “Slaves Waiting for Sale: Abolitionist Art and the American Slave Trade” (University of Chicago Press).

Her new book is one of half a dozen recent studies of how African-Americans were historically depicted. Scholars are deciphering what artists were expressing and how sitters were probably feeling, along with how audiences reacted.

“All of a sudden these histories started coming to the fore,” Agnes Lugo-Ortiz, an editor of an essay collection called “Slave Portraiture in the Atlantic World” (Cambridge University Press), due out this fall, said in a recent phone interview.

A book series, “The Image of the Black in Western Art,” has been in progress for decades and is now being released through Harvard University Press. In the latest two volumes, the historian Hugh Honour analyzes depictions of proud runaways on horseback, liveried servants nearly hidden in the background in portraits of the founding fathers, torture victims in chains and light-skinned girls being sold into prostitution.

Mr. Honour found descriptions of the artists’ interactions with models. The prolific sculptor John Rogers posed a barefoot black man in his studio to portray a defiant field hand beside a tearful mother and toddlers at a Southern auction podium. The hired model’s stance was so realistic, Rogers wrote, “He fairly makes a chill run over me when I look at him.”

Reproductions of this sculptor’s 1859 work “The Slave Auction” did not catch on with his clientele. “None of the stores will receive it to sell for fear of offending their Southern customers,” Rogers wrote.

Pictures of slaves did prove marketable among aristocrats and abolitionists in England and on the Continent. In “Faces of Perfect Ebony: Encountering Atlantic Slavery in Imperial Britain” (Harvard University Press), the historian Catherine Molineux explains how European arts patrons liked to be portrayed alongside black servants cheerfully carrying parasols and exotic produce. Field workers’ lives were idealized in popular paintings and prints, especially in scenes of tobacco farms.

“In the absence of shackles, whips or collars, these black figures often appear to be voluntarily trading with Britons in a product they both appreciate,” Ms. Molineux writes.

Black artists who managed to train and travel in Europe also catered to white tastes for images of slaves. The Harvard series reproduces Robert Seldon Duncanson’s painting of Uncle Tom and Little Eva (based on Harriet Beecher Stowe’s characters) at an idyllic harbor and Edmonia Lewis’s Carrara marble statue of a black man and an American Indian woman breaking out of chains.

In “Slave Portraiture” the historian Eric Slauter reflects on how little is known about Scipio Moorhead, a friend of the poet Phillis Wheatley. Wheatley wrote a 1773 poem addressed to him as a “young African painter”; when he drew, she wrote to him, “breathing figures learn from thee to live.”

Scipio Moorhead belonged to John Moorhead, a Presbyterian minister in Boston. The minister’s wife, Sarah, a poet and artist, may have taught their slave to paint. But his archival trail seems to dissipate in 1775. His masters died, and the estate was broken up while he was probably still a teenager, and whoever bought him would have changed his last name.