Looking around on the web, like here:
http://www.aeragon.com/03/index.html
This says:
"B. Tyler Henry was granted a patent for a lever-action-repeating rifle on 16 October, 1860. The design was an improvement on the earlier volcanic rifle. "
The "volcanic" was actually invented by Smith and Wesson. They sold it to Mr. Winchester.
So Mr. Henry was building on their work.
Mr Smith went to Europe some time before this, and looked at European cartridges. The volcanic didn't sell or work very well, so they sold it. At about this time, the Colt revolver patent expired, and Smith and Wesson got the Rollin White patent on drilled through revolver cylinders.
Mr. Wesson developed the improved rimfire 22 cartridge. It looks like he put powder into the 22 BB cap cartridge, which had existed since 1845, but just had primer.
http://en.wikipedia.org/wiki/Rimfire
Speaking as an engineer, let me tell you that the path of development of technology is generally long and torturous, and there are lots of people involved. The technology improves by little bits until it finally becomes fairly usable. Then, sometimes, those folks get credit. The .22 rimfire is certainly one of those points.
The Henry, the Winchester, the volcanic, the lever action rifle, whatever the heck it is, didn't really hit its stride until centerfire cartridges were available. IMHO. Because rimfire cartridges had to have flexible rims, they could not (cannot) handle the chamber pressures that centerfire cartridges can.