Being a bishop, M. Valančius accomplished much in the sphere of public education and culture. He was establishing parochial schools, took care of publishing and distribution of Lithuanian books, organized a wide net of temperance societies that tried to divert the peasants from alcohol.
M. Valančius started his active literary career immediately after the interdiction of Lithuanian press. He published such books of prose as "The book of Children" (1864), "The book of Adult People" (1868), "Juzė from Palanga" (1869), "The Narration of Antanas the Franciscan Observant" (1872), "The Lives of the Saints" in two volumes (1858-1868). Among his contemporary didactic Lithuanian prose M. Valančius's works were distinguished by their literary values. M. Valančius laid the grounds of a Lithuanian realistic prose of higher quality that became dominant in Lithuanian literature of the last decade of 19th century.
M. Valančius died on May 17 in the year 1875.
His works were published under the name of Valančiauskas.