Acquaintance with Vladas Mironas, a close friend of President Antanas Smetona, helped Lapėnas launch his career within the Nationalist Union.

He became chairman of the union, but was demoted due to disagreements with Smetona over the party's role in the Lithuanian government.

In September 1935, Lapėnas was arrested on corruption charges because Maistas sold meat to a shop owned by his brother at prices far below the market.

Jonas Lapėnas was born on 5 August 1891 in Dagilynė [lt] near Pasvalys in present-day northern Lithuania.

His parents were likely poor farm workers at the Dagilynė Manor [lt] which was owned by Otto von der Ropp.

[3] Mironas was a close friend of President Antanas Smetona and an influential figure in the Lithuanian Nationalist Union.

[1] Lapėnas was elected chairman of the Nationalist Union in October 1929, replacing Vytautas Vileišis [lt] who became the Minister of Communications.

[5] At the time, the Nationalist Union was experiencing an internal crisis with the ouster of Prime Minister Augustinas Voldemaras and struggle for loyalty within the Iron Wolf organization.

Lapėnas thought that the Nationalist Union should become a ruling party and a deciding voice in state affairs.

[9] In April 1936, Šiauliai District Court sentenced him to eight years in prison and ordered him to repay 500,000 litas to Maistas.

[3] In 1932, Lapėnas built a modernist six-floor building by architect Feliksas Vizbaras [lt] at the center of Kaunas (present-day Kęstučio g.