How many years passed by between Patent # 1,000,000 and patent #2,000,000?
How were both of them related?

Patent number 1 million was issued in 1911. Patent number 2 million was issued in 1935. Source. According to my math, 24 years passed between, give or take a few months.

From the same source: "In 1961, patent number 3 million was issued. In 1975, patent number 4 million was issued and in 1991 patent number 5 million was issued."

April 30, 1935, historical US patent # 2,000,000 was issued to Joseph Ledwinka for a vehicle wheel construction. I couldn't directly find anything on #1,000,000. I registered with US-Patent-Search.com in order to download said patent, only to be told that I have to wait three more days. Patently absurd. So I'll keep looking elsewhere, though I have a feeling someone else will scoop me...

Good answer Professor. Patent #1000000 was issued to Francis Holton,from Akron,Ohio,in 1911 (as you mentionned). Don't need to wait 3 days.

Source

Both inventions had to do with vehicule tires.

Congrats for your EOTM AWARD.

Sincere thanks, mozart.

I wonder if Mr. Holton was with Goodyear, also in Akron OH. According to Goodyear.com, 1911 was also the first year they began building blimps.