The Accusative Case
Is the accusative case in Latin the same as in Esperanto (meaning prepositions take away the accusative case)?
Prepositions in Latin do not 'take away' the accusative. It is more that they take specific cases, and if it takes multiple cases, the case used can change the meaning.
in urbe (in using the ablative) -> in the city
in urbem (in using the accusative) -> into the city.
Esperanto also doesn't always take away the accusative, often when a preposition is followed by the accusative case it implies movement:
en la urbo -> in the city
en la urbon (urbo in the accusative) -> into the city.