Short answers, pulled from the story.
A she-wolf nursed the twins Romulus and Remus after they were abandoned by King Amulius of Alba Longa. The creature cared for the infants at her den, a cave known as the Lupercal, until they were discovered by a shepherd named Faustulus.
The earliest depiction of the complete icon with the characteristic turning of the She-Wolf's head backward and downward at the twins appeared on silver didrachm coins minted in 269 BC. This imagery became more recognizable than other symbols of the city such as Roma or the Roman eagle as the Roman world expanded.
The servant left the basket in standing water that had formed at the foot of Palatine Hill because flooding prevented him from reaching the intended spot where the current was stronger. Dionysius reports that rains raised the water so much that the servant had to abandon the twins there before the current receded.
To the Roman god Mars, the wolf is a sacred animal within ancient mythology. There is an ongoing debate about a connection between this sacred status and the ancient Roman festival of the Lupercalia which centers on the tale of the Lupercal.
The Fascist government of Benito Mussolini used the She-Wolf as a symbol while in power to transform an ancient mythological creature into a tool for national identity and regime legitimacy. By invoking the she-wolf, Mussolini sought to establish a lineage of strength and divine favor for his administration connecting the modern Italian state directly to its legendary origins under Romulus and Remus.