Chicken is cheap animal food easily raised and gaining weight quickly and efficiently. Whether slaves or workers or general "Southerners", they can be fed economically with chicken. Whether doing it themselves or being provided food from master or employer. Plus, it tastes so good it is the yard stick for almost everything else; although "tastes like chicken" is likely another stereotype…
Chicken was arguably more popular in the South, as was slavery, and among poor people in general, and thus I conclude that the origin of 'negroes love chicken' was greatly enforced by Northern eyes, even if it cannot be the only source for that and that 'they' did not create the stereotype.
For black Americans, additional associations are evident. The nos- talgia evoked by a family's fried chicken recipe is balanced by the me- dia's insistence on perpetuating negative stereotypes of blacks as unscrupulous chicken thieves and rapacious consumers of fried chicken. If we consider the major meat groups in America as chicken, pork, and beef, chicken is generally considered to be the least expen- sive. Chickens are easier to raise on poor "dirt farms," making them an inexpensive source of high quality protein. Throughout history, African Americans have had more access to chickens than to other meat sources. Further, if one intended to steal an animal for its meat, a chicken would certainly be most available. During and after slavery, blacks had limited access to food. In order to feed their families, some African Americans stole chickens.
The image of the African American as a shameless chicken thief is sharpened by depictions of unkempt blacks devouring fried chicken, permeating American popular culture. In D. W. Griffith's classic depiction of the reconstruction era, Birth of a Nation, blacks elected to the state legislature sit in the chambers, eating chicken and casually tossing the bones across the aisles. African Americans are understandably disturbed by the persistent coupling of blacks with sloppy foods eaten by hand (e.g., fried chicken, ribs, corn on the cob, watermelon).
–– Gary Alan Fine & Patricia Turner: "Contemporary Legends and Claims of Corporate Malfeasance: Race, Fried Chicken, and the Marketplace", 50 DEPAUL L. REV. 635 (2001).
However, getting any closer might not lead that far on the timeline backwards, as the stereotype seems to be quite old:
The June 12, 1864, issue of the New York Herald contained the article "Not ‘All Quiet Along the Lines.'" The article indicated that rebel soldiers were wasting their ammunition and drummers and that "demoralized negroes" were engaged in coffee boiling and chicken roasting "or some other delightful epicurean occupation denied to the gallant soldiers who front the enemy."
So deeply embedded were these assumptions about African Americans and chicken that they were deemed an important point of reference for a Civil War reporter.
The irony here is that while these unfortunate black soldiers were participating in the war to free themselves from enslavement, the condescending rhetoric of this article illustrates the quagmire that daily confronted them, as stereotypes of this nature were inescapable. These kinds of historical references certainly helped to fuel what we understand today to be the stereotypes that distort the perceived relationships that black people have to chicken. Although the exact origins of this stereotype are unknown, narratives from the eighteenth and nineteenth centuries coupled with visual imagery and other ephemera of the twentieth century suggest the beginning of a perennial racial stereotype that continues to persist.
–– Psyche A Williams-Forson: "Building Houses out of Chicken Legs. Black Women, Food and Power", University of North Carolina Press: Chapel Hill, 2006.
Also –– Psyche Williams-Forson: "More than Just the “Big Piece of Chicken”: The Power of Race, Class, and Food in American Consciousness" in: Carole Counihan & Penny van Esterik: "Food and Culture. A Reader", Routledge: London, New York, 32013.