While you are mentioning traditional slide players, don't forget Maybelle Carter of the Carter Family. She used an ordinary wooden guitar with something over the bridge to raise the strings. She played it on her lap using a wide variety of tunings. The slide she used was the "Hawaian" type--essentially a a solid bar of metal with a slight flange to rest your fingers on.

The tune in her "Little Darlin' Pal of Mine" was adopted by Woody Guthrie in his "This Land is Your Land".

She gets a different effect from the black slide guitarists mention above.

Murray