Answer:
I think that the conclusion that I can draw in regards to him helping Hilary is that he endorsed her. The words of a former US President would likely make Hilary look really good in the limelight. Which is what happened. Since Obama was fond of her and publicly endorsed her, people thought she'd be a good choice in terms of Obama's judgement.
Plants that once were only found in the America’s account for 1/3 of the worlds food supply today.
they claimed that without slaves the economy would collapse I think, I'm not quite sure if I'm remembering correctly though
One is the social reform movement.