Its name is generally agreed to derive from ki ngombo, the term for okra in the Central Bantu dialect of West Africa, the homeland of many of the slaves brought to colonial Louisiana. Okra stews, served with rice, were a staple food among those slaves. And okra is the main thickening agent in many (though not all) varieties of gumbo. So it seems reasonable to conclude, as many culinary historians have, that the dish itself also bears some African heritage.
Nevertheless, a debate about gumbo's precise origins has raged for decades, framed by Louisiana's legacy of colonialism and complicated by the vast range of gumbo-preparation techniques practiced by the different peoples who make up the region's complex ethnic fabric. Most gumbos achieve their thickness, color, and texture partly from the use of a roux, the mixture of flour and oil employed by French cooks as early as the 14th century. This French technique has sometimes been used to bolster the theory that gumbo derived not from African okra stews, but from French bouillabaisse. Another theory contends that gumbo originated with Native Americans. That idea draws support from the use of the ground sassafras called filé powder as a thickening agent in some gumbos. According to this account, filé was introduced to the French by the Choctaws, whose word for sassafras was kombo.
Of course, like most Louisiana recipes, the ingredients you use depends on what's in season and in your cupboard. Link
(image credit: Justin Vogt)