Putting emotions aside for a second, slavery is very inefficient in a free market. It is not a coincidence free countries are all capitalist (and vice versa).
When did markets cause famine? We are living in an age of wasted food because we have so much cheap crap (as well as high-quality) available. People are too fat because there's no barrier to over-consumption.
Whereas a socialist system causes famines due to central planning leads to poor decision making.
How would socialism have dealt with the first scenario? My understanding is there simply wasn't enough food to go around, and no economic system can fix that. Capitalism at least provides a profit motive to solve the problem (eventually).
The Bengal famine was a top down project specifically designed to profit. There is no "free market capitalism" in that scenario.
Oh yeah. The US is guilty as charged, but there's no such thing as a free country that's not capitalist, until we live in a post-scarcity society. Technologically we are many centuries away from that.