Q: Where are the descendants of the old Slovak immigrants?
The last usable census for this information is the one from 1990. It contained questions about people's heritage that everyone answered and the data were collected before communism collapsed in Europe and a fresh wave of Slovak immigrants started to arrive.
Of all the counties in the United States, the highest percentage of people who reported full or partial Slovak heritage in 1990 was in Allegheny County, which includes Pittsburgh, PA.
The Slovak-Americans were the 5th largest group there after the Germans, Italians, Irishmen, and Poles. Hazelwood, North Braddock, West Mifflin, and Duquesne had 24% – 54% residents with Slovak ancestry in 1990. Other boroughs that ranked above the county’s average were (from higher to lower) Clairton, McKeesport, Versailles, Swissvale, Braddock Hills, McKees Rocks, Springdale, and Tarentum.
It reflects the numbers from the time when most modern Slovak-Americans' ancestors arrived. In 1919, for instance, the Slovaks were the largest immigrant group in Homestead by far – about 4 times as large as the next group, the Rusyns, and five times as large as the Hungarians, Irishmen, or Poles.
S-W PA, N-E OH, N-E PA
Allegheny County (Pittsburgh) and nine nearby south-western Pennsylvania counties created the contiguous area of 10 of the top 15 U.S. counties with the highest density of Slovak-Americans – Westmoreland, Washington, Armstrong, Indiana, Clearfield, Cambria, Greene, Fayette, Somerset.
The three U.S. areas with the highest density of Slovak-Americans in 1990 were south-western Pennsylvania, north-eastern Ohio, and north-eastern Pennsylvania
The Slovaks' most common places of employment there before World War I were the steel-mills and mines. The areas were also important centers of Slovak journalism and fraternal life.
Many other U.S. areas had high absolute numbers of Slovak immigrants, but their ratio among the rest of the population was lower. Pennsylvania and Ohio were followed by Illinois and Connecticut in relative numbers at the state level. Next in line were (alphabetical order) Colorado, Delaware, Indiana, Maryland, Michigan, Minnesota, Nebraska, New Jersey, and New York.