What were advantages of having a curtain wall castle?

In medieval castles, the area surrounded by a curtain wall, with or without towers, is known as the bailey. The outermost walls with their integrated bastions and wall towers together make up the enceinte or main defensive line enclosing the site. Curtain wall is an outer covering of a building in which the outer walls are non-structural. It keeps the weather out and the occupants in. As the curtain wall is non-structural entity, it can be made of a lightweight material reducing construction costs.

the group i'm selecting: greeks.

a first group of greek immigrants came to the us in the 1850s. the second group came to america starting in the 1890s due to economic opportunities they didn't have back in their home caused by the hardships of ottoman rule. greek immigration was 90% male, many of them expected to work and return to greece after earning enough capital, but ultimately had to remain in the us after the greek genocide.