Although claiming immunity as a member of the National Assembly, he was arrested during a stay at the hotel "Stadt London" in Vienna and executed for his role in the Revolutions of 1848 in the German states.

Blum grew up in poverty in Cologne, the son of a failed theologian who made a poor living as a cooper.

His work was interrupted by obligatory military service, and on his release, his poor circumstances obliged him to return to Cologne.

That year he also founded the Schillerverein in Leipzig which celebrated the poet's anniversary as a festival in honor of political liberty.

In 1845, Blum organized the first German Catholic synod in Leipzig that marked the beginning of Germany's humanist free religious movement.

At a turbulent meeting of armed citizens and students of Leipzig, Blum dissuaded them from storming the barracks, and urged conformity to the law.

As the leader of the radical liberal faction, he strongly opposed the Malmö Treaty between Denmark and Prussia that abolished Schleswig-Holstein's democratically elected government.

Brought before a military tribunal, he pleaded in vain his privileges as a deputy from the German Diet and was condemned to be hanged, a sentence which was changed to death by the bullet.