Who do you think made some kickass contributions to mankind, but doesn’t get the public recognition they deserve? My vote: Norman Borlaug, the father of the green revolution. He allowed for the massive population growth and food increases in recent years, but I had to google his name.
Also, while Alexander Hamilton is certainly well known, I don’t think he and his exploits are placed on the same level as Washington, Jefferson, Franklin, as they should be.
Clearly, me. You can tell, because you’ve never even heard of me.
Well actually, you were cited quite a lot in my Introduction to Message Board Posting college seminar.
This is also my answer to “who is the most important person in history”, but since he’s relatively unknown, he qualifies here too: Stanislav Petrov. http://en.wikipedia.org/wiki/Stanislav_Petrov
I have to agree with Norman Borlaug as well. I got to attend a lecture of his and afterwards I shook his hand and thought to myself, “This is the closest I have ever been to true genius!”
I watched a documentary about the scientist Percy Julian once. It was fascinating and the whole time I was watching it I wondered why he wasn’t more well known. He was a pioneer in more than one way.
Theodore Judah was the original mastermind and engineer of the transcontinental railroad.
In his quest to drive a railroad over the Sierra Nevada Mountains, which many people thought impossible at the time, Judah sought funds and sold the “Big Four” on his idea and his plans. The Big Four then essentially took Judah’s ideas and plans and squeezed Judah out of all the power and riches that accompanied the project.
Sara Josephine Baker. The most underrated person in history- maybe not. But she quietly had a immense impact on infant mortality in NYC and implemented many basic practices that are commonplace now. She is credited with putting in place policies that saved hundreds of thousands of babies during her career alone.
A link from that link is to Vasili Alexandrovich Arkhipov. He was an officer on a nuclear-armed submarine during the Cuban missile crisis. A unanimous decision from three officers was needed to launch a nuke from the sub. While the ship was being harassed by American forces, Arkipov was the only dissenter, preventing nuclear war. Interesting stuff.
To clarify, he was a design engineer not an “I drive the train” engineer.
For American history I’d have to say Thomas Payne. Without “Common Sense” the average colonialist would never have revolted and when “The Crisis” was published the Revolution was on it’s last legs. Washngton never would have been able to pull of Trenton and aprinceton without Payne’s pamphlet.
I opened the thread to say Norman Borlaug and the OP nailed it.
Borlaug’s face should be on money. And he’s not even dead yet.
As did I…hmmm, if all of us are rating Borlaug, perhaps he’s not as underrated as we think? 
Eleanor Roosevelt, because she could fly!
Does anybody even know what Chinese inventor first concocted gunpowder?
Or the first human to figure out how to domesticate horses?
Or the first caveman to learn how to make fire?
All mighty important, but nobody knows their names!
Ask a random person who Michael Faraday is and they’ll have no idea. Considering that any and all modern electronics are quite literally unthinkable without his innovations, I’d say that makes him the most underrated person in history.
Didn’t he work a lot with cages? Or am I misremembering? 
Shocking that you wouldn’t know that!
Edward Jenner, pioneer of the smallpox vaccine
Oliver Wendell Holmes, Sr.who first published the link between sanitation and disease, even before Semmelweiss or Lister.
John Snowthe English physician who traced the 1854 cholera outbreak in London to a single contaminated well and introduced the scientific method to epidemiology.