Born in Adams County, Pennsylvania, from a German Baptist (Dunkard) background, she left home at an early age after her mother had died and her father remarried. She married Alexander McSween on August 23, 1873 in Atchison, Kansas and they settled in Eureka, Kansas. In 1875, the couple moved to Lincoln, New Mexico, where her husband had accepted a job with the company of Lawrence Murphy. Working alongside James Dolan, McSween soon lost his desire to work for the company, and had by that time become friends with John Tunstall, a wealthy English rancher. Through Tunstall, the couple met John Chisum, and by 1877 the three men had established a rival business to the Murphy-Dolan businesses who had completely monopolized every business transaction in Lincoln. The Murphy-Dolan faction was backed by the infamous Santa Fe Ring.
