When looking at the reasons for people moving out West, we also need to bear in mind the conditions of the major cities back East. The United States experienced a rapid period of urbanization during the nineteenth century. With this unprecedented change came the myriad problems associated with life in a growing city. Eastern cities such as Boston and New York experienced massive overcrowding, grinding poverty, crime, and high mortality levels. The quality of life for far too many people was exceptionally poor, prompting growing numbers to seek a better life for themselves elsewhere.
The West seemed like the natural place to relocate for those worn down by the horrors of urban life back East. With its plentiful land and wide-open spaces, the West provided a chance for people to start again, to take the myriad opportunities for prosperity and advancement opened up by the new frontier. Large numbers of immigrants had settled in the Eastern cities in search of opportunity. Yet many had become thoroughly disillusioned amidst all the squalor and rampant exploitation. For these people, the expansion of the West revived the original promise of America, the enduring self-image of the United States as a place of opportunity.