As a student at the Sejny Priest Seminary, was involved in the publication and distribution of the illegal Lithuanian publications. He was searched by the Tsarist police for violating the Lithuanian press ban and fled to United States where he completed his education at the St. Charles Borromeo Seminary. Ordained as a priest in 1896, was parson in various Lithuanian parishes in Pennsylvania and New York. In addition to his pastoral duties, Milukas was a member and co-founder of numerous Lithuanian American organizations and societies as well as a prolific Lithuanian-language book publisher and newspaper editor. Together with Julija Pranaitytė, Milukas published some 190 Lithuanian books. These included three-volume photo album compiled by Milukas and exhibited at the World's Fair in Paris, history of Lithuania translated into English by Milukas and distributed to diplomats at the Paris Peace Conference, 1919, four volumes on the history of Lithuanian Americans written by Milukas. He established and edited the quarterly cultural magazine ' (1898–1906) and edited the Catholic ' for forty years (1903–1943). He assisted in editing "Varpas" (1891–1892) and "Tėvynės sargas" and "Žinyčia" (1901–1902).