Mark Twain was able to catch a great deal of "local color" in his classic, The Adventures of Huckleberry Finn. It is easy to see these things as he moves from place to place telling stories of people Jim and Huck meet; these stories are threaded together by the Mississippi River that travels through each locale—bringing Huck and Jim to new adventures and, ultimately, carrying them away to safety or further adventures, danger, or a combination of all of these.
It is said that the Mississippi River unifies the variety of plot-centered threads that Twain follows with his characters. It also reflects the way life was for those who used the water to travel or to make their living: fishing, shipping goods, running a riverboat, etc.
Tradition is defined as...
...the handing down of statements, beliefs, legends, customs, information, etc., from generation to generation...; a long-established or inherited way of thinking or acting; a continuing pattern of culture beliefs or practices...
To me, it also means "customs," and there are several Huck Finn shares with the reader. First of all, the practice of keeping slaves is a tradition or custom passed down through many generations—often slaves would be inherited when someone in the family died. Miss Watson has owned Jim and sold his family, but at the end of the novel, she surprisingly frees Jim in her will.
In Chapter 17, revolving around the Grangerfords and the Shephersons, a preoccupation with the dead is also a cultural custom or tradition. Viewing old photo albums of the past, it is not unusual to see pictures of people after they have died.
Emmeline Grangerford, at age fifteen (she has since died), made pictures called "crayons," in which the women were in some stages of suffering loss. One young lady is standing against a tombstone. It is entitled, "Shall I Never See Thee More Alas." The next shows a young woman holding a dead bird in her hand, and is entitled, "I Shall Never Hear Thy Sweet Chirrup More Alas." The last shows a grieving woman holding a letter while she deals with terrible emotional pain; it is called, "And Art Thou Gone Yes Thou Art Gone Alas."
They was different from any pictures I ever see before—blacker, mostly, than is common.
From this we can infer that there are other "dark" pictures, but these are even blacker. In fact, the color black is abundant: the sealing wax on the letter, the ribbons tied around one young woman's ankles, along with black hat, black veil and dress. This preoccupation with death was not unusual for the time.
Even the more than thirty year-old feud between the families is not unheard of: we see an example in the play Romeo and Juliet. In this case, no one can be quite sure what started it, but it is passed on from one generation to the next without any reason other than that of tradition—it's always been that way.
Another tradition is that of raising dead bodies from the watery depths by firing a cannon over the river, etc. Loaves of bread with mercury in them, floating on the water, were also supposed to find dead bodies. This is a long-standing superstition:
Radford's Encyclopaedia of Superstition, by E. and M.A. Radford (1947), describes a "widespread" British superstition that "a gun fired over a corpse thought to be lying at the bottom of the sea or a river, will by concussion break the gall bladder, and thus cause the body to float."
These are among some of the traditions or customs of that day.