He was born on 10 December 1869 in a peasant family in Okrúhl. He received his primary education in Radom. At the age of sixteen he went to work in America, where he started as a miner in Hazelton, then a peddler in Freedland and spent his free time studying English. In 1893 he and his wife settled in Olyphant, where he conducted a hospitality and wine wholesale business. 

In time he established a shipping agency and in 1897 the private Bosak Privat Bank. In 1902 he was a member of the board of directors of the First National Bank in Olyphant, and five years later was its president, with the right to sign the $5, $10, and $20 bills issued by that bank (1907). In 1908 he moved to Scranton, where he opened a private bank and travel agency. Four years later he established the Slavonic Deposits State Bank in Wilkes Barre, the Bosak State Bank in Scranton in 1915, and the American State Bank in Pittsburg. 

He was also involved in the movement of the countrymen and during the First World War he initiated a million-dollar collection to agitate for the independence of Slovakia. He was a signatory of the Pittsburgh Agreement, which became the basis for the establishment of Czechoslovakia. In 1920, Bosák visited Slovakia and founded the American-Slovak Bank with headquarters in Bratislava and 12 branches, including Prague and Uzhhorod. 

For the needs of the bank's branch in Prešov he had a splendid Art Nouveau building built, known as Bosák's House, the former seat of the P. O. Hviezdoslav Regional Library. After some time, disappointed with developments in the new state, he decided to discontinue his activities in Slovakia, sold the bank in 1927 and returned to the USA, where his successful financial ventures, estimated at 15 million dollars, were hit by the economic crisis. In 1937 he was a member of a delegation of American Slovaks received by President Roosevelt. 

Shortly thereafter, on February 18, 1937, he died in Scranton. In 1976, on the occasion of the U.S. bicentennial, Bosák was listed among the fourteen most important Slovaks in American history. The Michal Bosák Society was founded in his honour in 1999 in Prešov.

Source: Regional Library P. O. Hviezdoslav in Prešov; Micro-project.
Photo source: Author unknown - Public domain - Kramerius Digital Libraryː https://kramerius5.nkp.cz/view/uuid:148383a0-7103-11e2-b9fa-005056827e52?page=uuid:77d2f740-90ae-11e2-a85c-001018b5eb5c, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=116473328