Career
He co-founded the Partito dei Lavoratori Italiani in 1892 after renouncing his anarchist principles in 1879. In his book My Years in Exile, Edward Bernstein wrote of the conversion: "When first heard the news that Costa was lost to the Anarchist cause, he excitedly raised his hands above his head, and cried repeatedly, almost in desperation: "Anna! Anna! Anna!"".
In his later years Costa was an active politician. He served as mayor of Imola and as a representative in the Italian Parliament.
He died in Imola in 1910.