Antanas Smetona was a member of the Lithuanian Democratic Party in 1902-1907; a leader of the Lithuanian Party of National Progress from 1920 to 1924, and an active participant in the activities of the Lithuanian Home Guard Union in 1924.The same year saw him among the founders of the Lithuanian Nationalist Union; soon thereafter, he became Chairman of the Union (1925-1926).

In 1932 Smetona was awarded the Honorary Doctor of Philosophy degree at Vytautas Magnus University.

From 1924 through to1940 he was the Vice-Chairman of the Board of the International Bank, founder and one of the leaders of a number of societies and companies.

Antanas Smetona contributed to "Vilniaus žinios" (Vilnius News), edited "Lietuvos ūkininkas" (The Lithuanian Farmer), published "Viltis" (The Hope), published and edited "Vairas"; he was publisher and executive editor of "Lithuanian aidas" (Lithuanian Echo). He publicized original and translated works on philosophy and other research papers.

Antanas Smetona died in a fire in Cleveland (U.S.) on 9 January 1944.