Answer:
Lyndon B. Johnson’s presidency.
Explanation:
I'm like 90% sure its this.
The landmark legislation that led to these far-reaching changes in immigration patterns occurred as a result of Lyndon B. Johnson’s presidency.
Immigration is the movement of people usually from a particular location where they reside to another location that is mostly better than the previous.
People migrate in search of food, shelter, security.
Therefore, The landmark legislation that led to these far-reaching changes in immigration patterns occurred as a result of Lyndon B. Johnson’s presidency.
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