Complex sentence: Hudson, who is Caucasian, submitted the poem and had been rejected 40 times under his own name before submitting it under the pseudonym of Yi-Fen Chou, putatively a Chinese female, when it was accepted for publication.
Split into simpler sentences: Hudson, who is Caucasian, submitted the poem and had been rejected 40 times under his own name. He then used the pen name of Yi-Fen Chou, putatively a Chinese female, and it was accepted for publication.