Carpathian Ruthenia is a small region in Central Europe, now mostly in western Ukraine, easternmost Slovakia, Poland and a few villages in Romania and Hungary.
Historically, this specific geographic area with defined ethno-linguistic boundaries in the northeast region of Austria-Hungary, encompassed part of Galicia and the old Hungarian counties of Saros, Zemplen, Szepes, Abauj, Ung, Ugocsa, Bereg and Maramaros. People from this Carpathian Mountains region were members of the Greek (Byzantine) Catholic Church (also called Uniate) and the Orthodox Church.
In ethnic diversity, it is inhabited by Ukrainian, Rusyn, Lemko, Hungarian, Slovak, Romanian, Bulgarian and Russian populations.
To read more about the Carpathian Ruthenia region see Wikipedia.
Lemkos are one of the ethnic groups inhabiting the Carpathian Mountains in what is now Southeastern Poland, formerly in the province of Galicia. Their language has been variously described as a Lemko language, a dialect of the Ukrainian language, a dialect of the Rusyn language and more recently sometimes described as a distinct dialect of the Slovak. In any case, the Lemko tongue and the Ukrainian language are akin but not always mutually intelligible. Rusyn (also referred to as the Ruthenian language) is similar to the Slovak language and Ukrainian language; Ukrainian scholars consider Rusyn a dialect of Ukrainian.
Hutsuls are an ethno-cultural group of Ukrainian highlanders who for centuries have inhabited the Carpathian mountains, mainly in Ukraine, the northern extremity of Romania (in the areas of Bukovina and Maramureş).
Ukrainian Hutsul culture bears a resemblance to neighboring cultures of western and southwestern Ukraine, particularly Lemkos and Boykos. These groups also share similarities with other Slavic highlander peoples, such as the Gorals in Poland and Slovakia. Similarities have also been noted with some Vlach cultures such as the Moravian Wallachians in the Czech Republic, as well as some cultures in Romania.
Most Hutsuls belong to the Ukrainian Greek Catholic Church and the Ukrainian Orthodox Church. The Hutsul language is relatively unusual. It is considered to be a dialect of Ukrainian with some Polish influences.
In St. Louis, Missouri, around 1900 many of the Ruthenian immigrants spoke "Slavish". Was this a Ruthenian dialect spoken in eastern Europe, or is it a dialect which developed among the eastern European immigrants after they arrived in America. A Czech immigrant Roman Catholic priest in St. Louis was able to communicate with the Ruthenian Greek Catholic immigrants attending his parish using the Slavish dialect.
It appears that there is not anything specifically identified as the Slavish language or dialect, but Slavish is a phonetic equivalent to the German way of saying Slavic: Slawisch. Rusyn is a Slavic language, in the same East Slavic language group as Russian, Ukrainian, and Belorussian. These four language came from the Old East Slavic language. Perhaps they referred to it as Slavish (or Slawisch) in the similar way that we say that the people are Slavic.