Sentence:  Nor have we remembered that in the melting pot of America the hundreds of isolated and semi isolated ethnic , regional and occupational groups did not fuse into a homogeneous national unit until long after education and industrialization had caused them to cast oral tradition aside as a means of carrying culturally significant <WSD>material</WSD> . 
Meaning of the word marked with <WSD> tags:  information (data or ideas or observations) that can be used or reworked into a finished form