Christiana is a borough in Lancaster County, Pennsylvania, United States. The population was 1,124 at the 2000 census. In 1851 it was the site of the Battle of Christiana (also called the Christiana riot).The present-day borough of Christiana was once known as Nobleville, Pennsylvania.According to the United States Census Bureau, the borough has a total area of 0.5 square miles (1.3 km2), all of it land.
On September 11, 1851, Christiana was the site of the Battle of Christiana (also called the Christiana riot), in which the local residents defended with firearms a fugitive slave, killing the slaveowner. Southerners demanded the hanging of those responsible, who were accused of treason and making war on the United States, but after the first defendant was acquitted, the government dropped the case. The trial was the first nationally-covered challenge to the Fugitive Slave Law of 1850.