ABSTRACT
American historians have long been conscious of the importance of physical movement. The crudest generalization, and the most common touchstone, of discussions of geographic mobility is the assertion that in the 20th century one out of five Americans moves each year. The greater the distance involved in a move, the more likely it is to disrupt the accustomed patterns of social and institutional associations in the migrant’s life. Quite obviously, a move across a street is less likely to weaken friendships and acquaintanceships than one across even a small town. The segregation of the ethnic groups in Chelsea in 1915 was quite substantial. As measured by the index of dissimilarity, a common statistical measure of segregation, the separation of old settlers, Jews, and Poles in Chelsea approached that which existed between the white and non-white populations of mid-20th-century American cities.
