Hi, Marianne!
 
I did a quick search, and it appears that the helicopter was invented quite a while before 1937, but didn't become really practical until the mid-30's.  Here's where I found the info:
 
http://www.vectorsite.net/avheli.html
 
and here is an excerpt from the first paragraph:
 
The concept of the helicopter goes back hundreds of years, and at the dawn of powered flight at the start of the 20th century, aviation pioneers believed that rotary-wing aircraft were right around the corner. In fact, while fixed-wing aircraft were quickly refined and improved, it wasn't until the mid-1930s that the helicopter began to emerge as a practical flying machine. This document outlines the early history of the helicopter, with a particular focus on early Sikorsky helicopters.
 
Hope this helps.  Myself, I don't know if the guy's dreams were real or not, but they sure were fascinating!  :-)
 
YSIC!
Peggy
www.his-forever.com