How was the Immigration Act of 1924 a means of fulfilling the desire of some Americans to stop the spread of “undesirables”, and why did they want them stopped?

Plz ive been stuck on this question forever. in 1753 george washington was sent on a mission to a. build a fort at the point where the allegheny and monongahela rivers form the ohio river. b. attack the french at fort duquesne. c. attack the french at fort neccessity. d. deliver a message to the french demanding that they leave the ohio river.