Born in German Pomerania (now Lębork, Poland), Sapir's parents emigrated to America when he was a child. He studied Germanic linguistics at Columbia, where he came under the influence of Franz Boas who inspired him to work on Native American languages.
With his solid linguistic background, Sapir became the one student of Boas to develop most completely the relationship between linguistics and anthropology. Sapir studied the ways in which language and culture influence each other, and he was interested in the relation between linguistic differences, and differences in cultural world views.
Most widely known for his contributions to the study of North American Indian languages.
A founder of ethnolinguistics, which considers the relationship of culture to language, he was also a principal developer of the American (descriptive) school of structural linguistics.
Ps: http://spruce.flint.umich.edu/~simoncu/269/sapir.htm ( a good link for this topic)