What was the territory of the Roman Republic at the end of the 6th century BC?

What was the territory of the Roman Republic at the end of the 6th century BC? What did it become by the middle of the 3rd century BC? how to explain the changes that have taken place?

In the 6th century BC, the newly created Roman Republic occupied the territory of the Apennine Peninsula. True, already in the 3rd century BC, its territories have changed significantly. So the republic included: the islands of Corsica, Sicily and Sardinia; almost the entire territory of Spain (that is, the Iberian Peninsula); southern regions of France; Greece and part of Asia Minor. This state of affairs is explained by the constant wars that the Romans waged in order to expand their lands.