 Between 1924 and 1927, Galvanauskas was accredited to the Court of St. James's in London and became Lithuania's ambassador to Great Britain.After the 1926 Lithuanian coup d'état he resigned from that post and returned to Klaipėda where he devoted himself mostly to teaching.In 1927-1928, he was chairman of Klaipėda's port board, chairman of Klaipėda's Teachers Society, and between 1934–1939 he established the Klaipėda Commerce Institute, and was its director.