Immigration to the United States surged in the 1850s in large part due to the tumultuous 1848 revolutions that took place across Europe. Major political upheavals affected countries including the German states, the Italian states, France, and Ireland, prompting many to leave home for the relative stability of the United States. Many of the new arrivals joined the Union Army to fight in the American Civil War.
Some made their homes in New York, including German immigrants Franz Sigel and Carl Schurz, and Hungarian Charles Zagonyi, all former officers in their respective homelands who were forced to flee to the United States following Prussian and Austrian oppression after the failed revolutions of 1848. Zagonyi served as an officer under John C Fremont in the American Civil War, but disappeared from the historical record after 1863. Franz Sigel also served in the Union Army during the American Civil War having fought in the Second Battle of Bull Run and achieving the rank of major general. He returned to New York City in 1867 and worked in education and journalism until his death in 1902. Schurz served with distinction as a general in the Union Army and following his military service continued to serve in a political capacity, first in Missouri and eventually moving to New York City in 1881. In New York, he spent the remainder of his life involved in journalism and politics, joining the Independents or Mugwumps, supporting Grover Cleveland in the 1884 presidential election.
Irish nationalist Thomas Meagher was convicted of sedition for his involvement in the Irish Rebellion of 1848 as the leader of the Young Irelanders, and was sentenced to be transported to Australia as punishment. He escaped Ireland in 1852 and settled in New York City. He joined the Union Army and rose to the rank of brigadier general, known particularly for recruiting and leading the Irish Brigade.