The earliest Slovaks to reach the shores of the United States are probably only known if their names were preserved because they were written in records, books, or articles someone has found.
One can read five articles on Slovaks who reached our shores and have five suggestions on which person that was. In the Chicago area we have examples too. Daniel Sustek and Geza Mihalotzy were in our area in the 1850's. Many references to both are found in multiple documents and articles.
When significant immigration of Slovaks to the United States and Chicago occurred, sometimes described as "waves", resources to describe and document those events are more readily available. Research articles, census records, newspaper stories, and more provide information.
Among all these publications, we even found a hint at an interesting competition. While searching for information on Slovak migration, we found an interesting article that describes, in the opinion of the author, that more Slovaks came or lived in the USA than their Czech neighbors.
There were some Slovaks who made it to Chicago before the start of the Civil War. A number, placed together under a name, were the “Kossuth migration”. Refugees from the Hungarian Conflict of 1848, Slovaks by birth or parentage, then part of the Hungarian region of the Austro Hungarian empire, defeated in this conflict, left and began arriving in the United States and Chicago area before the start of the Civil War. CSAGSI has researched such a person, Geza Mihalotzy, who became an officer of the 24th Illinois Infantry, fought in numerous battles, and died in battle in 1864.
CSAGSI also posted information on Daniel Schustek (Sustek), an early Slovak arrival to Chicago, who wrote numerous articles on life in the United States for a Slovak publication site. He also seemed to have been involved in several activities to help Slovaks reach and live in the Chicago area and other parts of the United States.
Writer, researcher, on Slovak history, migration, and more, Michael Kopanic (https://www.academia.edu/38193476/Slovaks_in_America) presents a summary which describes that the largest migration of Slovaks to the United States took place between 1880 and 1920. He describes that approximately one fifth of the entire population of Slovaks living in their homeland departed for the United States during this time period. Kopanic does mention that a large number of those who came to the United States did return to Europe. Kopanic and several other research publications describe that the early "waves" of this Slovak migration was from specific areas of the Slovak homeland.
Illinois and Chicago would not be the major destination for the earlier waves of migration from Slovakia. The area receiving the largest numbers would be along the east coast with a focus on the state of Pennsylvania.
For whatever reason a Slovak, or other European, would choose to leave their country and set out for the Unted States, Atlantic Ocean passenger ship lines, and USA railroad companies were eager to help them get to their desired destination. Business seeking new sources of labor and land companies wishing to sell to new settlers were just as eager. Though it should be noted that fewer Slovaks seem to have traveled, at least in the early waves of arrival, to areas of the United States to purchase land and farm. (Census Data Maps - shown below, seem to indicate that the greatest concentration of Slovaks by ancestry still appears to support that.)
Images Below: Passenger Ship Advertisement (1879 Kalendar, August Geringer Publisher, Chicago.) Railroads Advertisement (Library of Congress, Homestead Act)
Ohio, especially with all the online records available. Also would be an earlier destination for large numbers of Slovaks.
A 2012 USA map of Census Tracts continues to confirm that the areas claiming the largest Slovak ancestry are still in Pennsylvania, with a similar high percentage crossing the border into Ohio, running along the edge of the Great Lakes. Image below from 1933 World's Fair Czechs and Slovaks at World's Fair - Chicago - Census data on Slovaks.
"Streator was the early destination of the Slovaks in the State of Illinois. According to historical evidence, the first Slovak family known to have settled in that part of the State came in 1883. There is still a considerable number of the early Slovak settlers to be found in that town" (Illinois Catholic Historical Review", vol. 4, July 1921- April 1922, Published by Illinois Catholic Historical Society, Chicago, Pages 185 - 186)
"St. Stephen's Parish (Streator, Illinois) is the first Catholic parish established by Slovak immigrants in America. It was founded ca. 1883; its first priest was the Hungarian-educated Rev. Joseph Kassalko, who arrived in 1884. Under the direction of Rev. Kassalko's successor, Rev. Ervin Gelhoff, the St. Stephen's School, run by Franciscan Sisters, opened in the fall of 1888, the first Slovak school in the United States. Rev. Gelhoff, together with Rev. Stephen Furdek, later helped to found the First Catholic Slovak Union, in 1890. A new church was built in 1906, a new school in 1912, a new rectory in 1926, and a convent in 1958." (https://archives.lib.umn.edu/repositories/6/resources/4606) NOTE: In 2010 the Catholic churches / parishes in Streator were consolidated (https://thecatholicpost.com/2010/08/06/historic-changes-in-streator-as-four-parishes-to-consolidate/)
"Holy Trinity Lutheran Church was established by Slovak immigrates in 1884 and is considered the first Slovak Lutheran church in America. Worship Services were in the language of the people, Slovak. In 1894 the building of the “Old #3” church was completed. The church was built near the Chicago, Wilmington, & Vermilion Coal Co. mine no. 3 in south Streator. The mine operated from 1884 through 1896. Today the “Old #3” church is used only for special Services. In 1902, Holy Trinity joined with other Slovak Churches in America to form the Slovak Evangelical Lutheran Church. In 1971, the SELC merged with the Lutheran Church – Missouri Synod and remains as a non-geographic district of the LCMS." (https://holytrinitystreator.org/church/history/)
The Illinois Catholic Historical Review also described early Slovak settlement in Chicago beginning in the same year: "With the general progress of national life, there has been a continuous development of the Slovak population in Chicago. From the time of the early settlers down to the present day it has been found that the Slovaks possess qualities of character which fit them to become good, substantial citizens. They are conservative in all things, and always willing to accept with true enthusiasm, these fundamentals which tend to up-hold the true principles of the country. Chicago became the destination for the Slovaks as early as 1883, when a small group of Slovak immigrants arrived and settled on the West Side. Later another group arrived and settled on the North Side. There being no official record kept of the Slovaks settling in Chicago, it is difficult to give fully the names of the early arrivals. Through diligent search, and considerable inquiry among the Slovak people, the names of a few Slovaks, who settled here in the year of 1883, have been found. These being: John Sopeak, Jan Kelegda, Jan Laketek, and Jan Pajkos. These men of whom all are Catholics, are said to be the first important Slovak settlers in Chicago. Further investigation shows that there was found two Slovaks here as early as 1881. One, Arped Szolados, who was ‘‘Magyardized’’ and a Calvinist, though primarily, he was a Catholic, and A. Sloboda, said to be a Slovak nobleman." (Illinois Catholic Historical Review", vol. 4, July 1921- April 1922, Published by Illinois Catholic Historical Society, Chicago, Pages 185 - 186)
Wikipedia also lists the same time frame for Slovak migration, and provides a number of “approximately 500,000” with the majority settling in Pennsylvania. (https://en.wikipedia.org/wiki/Slovak_Americans) Wikipedia also mentions that it would become easier to find a number for Slovak immigration beginning in 1910, as the Census would begin listing Slovak as a choice for people to indicate on that census.
In 2016 Professor Janda presented an article describing that there may have been more Slovaks than Czechs in the USA. Online Version (PDF Format) Link Below.
The Cleveland area, in the past, an early settlement area for Slovaks, and today an area with a sizable Slovak ancestry, has numerous genealogy and Slovaks in Cleveland sites online.
Slovaks of Cleveland
Published in 1918 by the a member of the Cleveland Libary
Slovaks of Cleveland - http://www.briscar.com/featurepages/CleSlovaks.htm
Cleveland People - Slovaks
Facebook - Cleveland Slovaks
The Slovaks of Cleveland - Harvard University - Book on line
USA Census Data Site - Treasure Trove Of All USA statistics
Population listing by Ancestry
2021 - Czech and Slovak - Neither group listed in top 30 populations reporting their ancestry
American Community Survey Data
2013 Those reporting Ancestry
Slovak listed first - 435,432 Czech listed first - 830,195
Slovek listed second - 284, 771 Czech listed second - 617,240
2021 Updated Projections / Estimates
Population listing Slovak Ancestry - 594,844
Population listing Czech Ancestry - 1,252,833
Map Below 1880 Map from Wikipedia - Ethnic Distribution in Slovakia