Haiti - surprise -- it's all about oil and strategic minerals!!
I recommend you read the enclosed article with the same title as this blog - so you can understand why the USA has sent so many troops to Haiti and what their real purpose is.
Sure they want to help the people ... and earn their loyalty and support, but for economic and strategic reasons primarily and humanitarian reasons secondarily.
It also explains - why the US has been blocking the efforts of other countries, notably Cuba and Venezuela to help the Haitians.