Achieved the rank of lieutenant-colonel in the Spanish army. He condemned the assault of some Spanish officers to the journal La Veu de Catalunya in 1905, and was then forced to abandon the army.
He was representative for Barcelona from 1914 to 1923.
In 1926 attempted an armed action against the Spanish dictatorship of Primo de Rivera from Prats de Mollˇ (Roussillon), that was aborted by the French Gendarmerie, but that gained a lot of popularity for his cause in Catalonia.
In 1931, after the elections that caused the exile of Alfonso XIII of Spain, and that gave the majority to his party Esquerra Republicana de Catalunya, MaciÓ proclaimed the Free Catalan Republic in Barcelona, but was forced afterwards to change that to partial autonomy inside the new Spanish republic. MaciÓ was the President of Generalitat since 1932 to his death in 1933.