Had been the cultural and artistic center of the western world in the late nineteenth and early twentieth centuries, but new york city assumed that role in the mid-twentieth century.

Paris.

Explanation:

After the second world war Pairs has declined from the artistic center stage of the world and New York has taken its position. New York has been home to many cultural movements which includes Harlem renaissance, African-American renaissance, etc. The contribution of various ethnic groups is significant to its cultural development. On the other hand, Paris has lost its evolving cultural growth.