There are a number of births in Przersol, Suwalki Gubernia, Biyalstok Province, Poland that indicate that Mordechai Margolis was deceased by 1850, namely his grandson and great grandson (respectively):

• KALWARYJSKI Mortchaj 1850 B 12 son of Icko and Ryszka (daughter of Abraham) 747,007
• KALWARYJSKA Mortchaj 1852 B 8 son of Osier and Szejna Bejla (daughter of Chaimowna) 747,007
• According to Dr. Neil Rosenstein: born Kalwariya circa 1780 and died Kalwaryia 1846.

"Mordecai Margolis of Kalwariya in the north-east province of Suwalki, Poland, was the father of five sons (see the introduction to Nachalat Asher by his grandson). The eldest son was Judah Leib. His children and descendants adopted the name of Kalwaryiski-Margolis. The official records in Polish (available from the Mormon Church) mostly omit the Margolis part of the surname.

• Mordecai's wife was Hinde, daughter of Ber, or Berko in the Mormon microfilm records.
• The family origins can be found recorded in "Ohalei Shem" (Pinsk, 1912), by Samuel Noach Gottlieb (page 342) and in "Toldot Anshei Shem" (Warsaw, 1875), by David Tebele Efrati (page 23).
• In Chapter II of The Unbroken Chain, which traces the Katzenellenbogen Family (R. Meir Katzenellenbogen 1st generation), he gives the following generation to Mordechai Margolis:

1. R. Meir
2. R. Samuel Judah
3. R. Saul Wahl "King for a Night"
4. R. Meir Wahl
5. R. Moses of Chelm
6. Hanale, married in 1643 to R. Nathan HaLevi, son of R. Zeev Wolf (son-in-law of R. Yom Tov Lipman Heller)
7. R. Moses HaLevi Heller
8. Wife, born about 1670, of R. Samuel Schick
9. Wife of R. Mordechai Margolis

• Children of Mordechai Margolis and daughter of R. Samuel Schick

10.1 R. Asher "the great" of Grodno

10.2 Samuel Margolis

10.3 Ittel, died aged ninety one and was buried in Merkine (Meretz), married Eliezer Pruzhiner of Walkavisk, ancestor of the Efrati Family, who died in 1846. He was the son of R. Hanoch Heinich, ABD Kalwarija and Zabludow, near Bialystok

• Children of Ittel Margolis Pruzhiner -

1. Haim
2. Menachem
3. Mendel
4. Judah
5. Issac of Vistytis

11 Mordechai Margolis son of Samuel

• Children of Mordechai:

1. Kaila Bernstein, died about 1880 in Germany
2. Abraham Margolis, born about 1820, died about 1856 in Kalwarija
3. Elijah Margolis, born in 1807, died in 1867 in Rokishok
4. Sulka Sterlig, died about 1860 in Kalwarija
5. Jacob Margolis, born in 1812, died about 1862 in Baklerove
6. Zvi Hirsch Margolis, born about 1810, died about 1890
7. Judah Leib Margolis, 1798 - 1837

• From The Unbroken Chain (Dr. Neil Rosenstein) 1990 Vol 1, page 18. "Mordechai Margolis died in 1846, the progenitor of the Margolis Family. He settled in Kalwariya and some of his children settled in the small town of Przerosl, Suwalki district. Others became rabbis of towns such as Wizanjny, Alikst, Rokishok (Rokiskis) and Dzisna. During the latter half of the nineteenth century some family members came to the USA and settled mainly in New York, Dayton, Ohio, Peoria, Illinois, and Abbeville, South Carolina.
• Rosenstein refers the reader then to his 1984 book The Margolis Family (1984 out of print) for "full genealogical details of this large family".

Sources

• The Unbroken Chain by Dr. Neil Rosenstein, Vol 1 2nd edition, page 18. Paragraph G.11
• The Margolis Family by Dr. Neil Rosenstein, 1984.