In 1919, Matas Šalčius, together with Antanas Vienuolis-Žukauskas, Faustas Kirša [lt] and other employees of the Press Office decided to form an organisation that would protect Kaunas; they intended to call it the Steel Battalion.

Putvinskis stated that: "the Riflemen's Union is an organisation of free citizens, who volunteer their time and efforts for the sake of protecting their homeland."

After its establishment in 1919, the LRU quickly expanded throughout Lithuania; many guerilla fighters from recent wars joined the Union.

The riflemen's units had theatres, libraries, and sport clubs alongside orchestras and military bands.

To help with that they aimed at building riflemen centres in all cities and towns, where the union was active, with their duty being to national defense.

The centres served as meeting and training places for riflemen, and housing their clubs, administration and cultural activities.

In 1921, 1924, and 1935, laws on the LRU were passed that defined its activities and functions, intended to restrict its autonomy and tie it as closely as possible to the Ministry of Defence and the armed forces.

The law abolished dual leadership – previously the organisation had been led by the Chairman of the Central Board, elected by riflemen, and by the LRU Commander, appointed by the Minister of Defence.

[3] On 15 June 1940, the Soviet Union occupied Lithuania, and the riflemen, like the rest of the military, were ordered not to resist.

Aleksandras Barauskas, a rifleman and border guard, was killed by Red Army soldiers in the early morning of June 15.

In June 1941, the Soviets started a mass deportation that targeted "anti-Soviet elements", including the riflemen.

The remaining riflemen began forming anti-Soviet groups and played a role in the uprising of 23 June 1941, but there is no specific data on how many members participated.

During the Nazi occupation, ex-riflemen formed several underground organisations, such as Laisvės šauliai (Freedom's Riflemen), aimed at restoring Lithuania's independence.

Two out of eight guerrillas who signed the declaration of the Union of Lithuanian Freedom Fighters on 16 February 1949, were ex-riflemen: Leonardas Grigonis-Užpalis and Juozas Šibaila-Merainis.

Some other ex-riflemen were also prominent among the guerrillas, including Juozas Vitkus-Kazimieraitis, Zigmas Drunga-Mykolas Jonas, Dominykas Jėčys-Ąžuolis, and Vladas Montvydas-Žemaitis.

On 1 June 1989, during a protest in Kaunas by a club of former exiles and the Democrat party, the restoration of the LRU was officially announced.

Currently, the LRU is divided into ten riflemen regiments (šaulių rinktinė): After Lithuania re-established independence in 1990, the organization was restored but it has not regained its former popularity or influence.

The LRU Command also operates a militia band, guard of honor company, a sport and technology club.

It decides on the most important matters of the Organisation, adopts decisions and approves the Commander of the LRU who is selected by the Minister of Defence.

Members participate in the activities of the LRU, help in organizing the summer camps for young riflemen, cooperate with other university organisations.

It is headed by Julius Butkus and is active in the United States and Canada, and supports both the Union and the Armed Forces.