Mussolini did a lot of things, as /u/AlviseFalier mentioned. He was a totalitarian ruler of Italy for the great majority of that time, and the effects of his regime are still felt to this day throughout the entirity of the country (up to and including the fact that the club I support was founded due to Mussolini's influence and directives). A brief summation is difficult, and would not do justice.

Thankfully, I've answered versions of this question multiple times:

• Here I discuss the long term consequences of Mussolini and the Fascists on both the trains of Italy, and football. Especially their propaganda purposes.

• /u/Klesk_vs_Xaero and I teamed up to give some background on how the Fascists medled with economics, and industry here.
• Also of interest, possibly, is this answer where I discuss the nature of HOW Mussolini had as much power as he did as he should have been subordinated to the King.