Yechiel Reuven (Rubin)  Mandelbaum was born on Dec 8 1880 in Mogielnica,Poland. He lived in Ostrowiec and was a student of the Ostrovtzer Rebbe Meir Yechiel Halevi. He wrote down and gathered a lot of the Rebbe's works.

He married Hinda (Ajzenman) and their children were:

Tzipora- later married Menchem Rivlin. Among their children was Nechama Dvora  who married Shlomo Miller, who is a Rabbi in Toronto.  (Info provided by Yidel Miller, son of Shalom Miller and grandson of Shlomo Miller)

Lea

Yerachmiel -b. 1920

Naftali

Yisrael Chaim

It is told, that the Rabbi told Yechiel that he should consider emigrating from Poland and therefore around 1928, he moved to Brazil alone to check out the country. After seeing that Brazil lacks the Tora environment he was looking for, he them moved to New York to check it out. Later he brought the rest of his family to the USA.

Yechiel published in the late 1940's various notes of what he and other talmidim wrote down of ther  of the Ostrovtzer Rebbe's shiurim and gathered them in a book Meir Enai Chachamim in 2 volumes  .

Years later, his son Yerachmiel continue his father's work and re-published his father's work along with updates and created a 3^rd volume .

Yerachmiel's family established in Israel Machon Meir Enai Chachamim …. had a desire to make the publications easier to be understood and more concise and published volumes on the Chumash and Zmirot and future on Shas