Question:
What are some limitations when it comes to determining the cause of an event?

Some limitations when determining the cause of an event are that other sources that are linked to the event in the same time can usually say things different; It is especially difficult if there is no solid base to the cause and no photographic or written evidence.

the group i'm selecting: greeks.

a first group of greek immigrants came to the us in the 1850s. the second group came to america starting in the 1890s due to economic opportunities they didn't have back in their home caused by the hardships of ottoman rule. greek immigration was 90% male, many of them expected to work and return to greece after earning enough capital, but ultimately had to remain in the us after the greek genocide.