Nearly 5.4 million South Asians live in the U.S., most of whom trace their roots to Bangladesh, Bhutan, India, Nepal, Pakistan or Sri Lanka, according to the group South Asian Americans Leading Together. In many of these communities, a 3,000-year-old social hierarchical system known as caste is still prevalent. On Feb. 21, Seattle became the first U.S. city to ban caste- based discrimination by incorporating it into its anti-discrimination laws.