Answer:
Following the Bolshevik Revolution in Russia in November 1917, the sense of an inevitable foreign or communist threat grew among those already predisposed to distrust immigrants. The sense of fear and anxiety over the rising tide of immigration came to a head with the trial of Nicola Sacco and Bartolomeo Vanzetti.
Step-by-step explanation:
Disease of all kinds (including cholera, typhus, tuberculosis, and mental illness) resulted from these miserable living conditions. Irish immigrants sometimes faced hostility from other groups in the U.S., and were accused of spreading disease and blamed for the unsanitary conditions many lived in.