Complex sentence: Other Chinese men traveled back to China as a Unites States citizen, report that their wives have given birth to a son which makes the child eligible to be a United States citizen, and receive a document for it.
Split into simpler sentences: Other Chinese men would travel back to China as United States citizens and report that their wives had given birth to a son. Consequently, this made the child eligible to be a United States citizen in which they would receive a document for it.