On the East Coast, immigrants entered the United States through the inspection stations on Ellis Islands. Immigrants had to pass through what
Island on the West Coast.

Explanation:

Angel Island Immigration Station (San Francisco). The great influx of immigration took place mostly in the early 1900s where Ellis Island and This Immigration station were busiest and largest. The needs were different on the west coast than on Ellis Island. Mining rails were the most common industries needing help from Immigrants.

answer: the ocean

explanation: if you map out 30 n and 40 n latitude, you will get the ocean