What were the reasons behind anti-immigration movements in the early 1900's?

There was a problem with illegal immigration in the 1900's, so therefore anti-immigration movements were formed

Assemblies do not have written codes of laws. laws are matters for magistrates and courts, not assemblies. codes of law are things such as civil law, criminal law, and constitutional law. what assemblies have are procedures regarding debating, voting and other business they might carry out.  also note that rome had three assemblies: the assembly of the soldiers, the assembly of the tribes, and the plebeian councils.