Complex sentence: By the mid- 19th century, due to the British pressure to end the slave trade, plantations owners brought over 100,000 Chinese who were held in conditions not very different from the ones of the African slaves.
Split into simpler sentences: By the mid- 19th century, due to the British pressure to abolish slavery, plantation owners transported more than 100,000 Chinese workers. But they were held in conditions not very different from the ones of the African slaves.