The introduction of Frank Caldwell's variable-pitch propeller made Hamilton Standard one of the leading aerospace companies of today.

Hamilton worked hard from an early age to understand technical concepts and their application to aircraft design and manufacturing.

His mother had taken a trip to see the 1904 St. Louis Exposition, where there was a display of gliders organized by Octave Chanute and, somehow on her return, Hamilton became more focused on aeronautics.

This job would also allow him to ride what he repaired (possibly a type of insurance policy to ensure the balloons were fixed properly) which helped fuel his continuing interest in aviation.

Three gliders were actually built and flown around the steep hills around their neighborhood in Seattle called Leschi which was on the west shores of Lake Washington.

At this point, there was a disagreement between Palmer and Hamilton, and the former was no longer involved with the company and was totally removed from the partnership.

Incidentally, Hamilton and Boeing became friends during this time and their friendship lasted throughout the years both professionally and personally.

They were looking for someone to build airplanes for the non-profit, private BC Aviation School Ltd. that would teach their Canadian sons to fly in the Great War being fought over in Europe.

It was a biplane patterned after a Curtiss tractor design, with two seats, a six-cylinder engine, and a tricycle landing gear.

In the meantime, Hamilton had become very interested in the physics of propellers and had started making inquires about his possible involvement in the war effort for the United States.

The military leaders at the time wanted to keep most of their aviation resources closer to Washington D.C., and not in the remote Pacific Northwest.

A Milwaukee woodworking firm, the Matthews Brothers Furniture Company, needed an experienced person to run their new aviation division since a large military contract was signed to produce wood propellers for the Navy and Army.

The Hamiltons spent ten years in Milwaukee, where it was established as one of the nation's major aviation hubs in the 1920s.

[5] Despite the clear advantages, there was initially a strong resistance to using materials that rusted easily but this changed with the widespread introduction of a new aluminum alloy developed at Zeppelin.

It used a tubular frame with corrugated skin, a thick monoplane wing projecting from the fuselage beneath an open cockpit, with a 200 hp (150 kW) Wright J-4 Radial engine in the nose, and using a Hamilton (metal) propeller.

One of the interesting concepts, was when the designers took the H-18 and fitted two large downward facing propellers (i.e. on under each wing at midpoint) driven by a small engine mounted in the fuselage.

For this reason, the Hamilton Metal plane struggled in the market, for it was a good airplane developed ahead of its time.

Hamilton's entire family moved to Beverly Hills and eventually built a house out at Lake Arrowhead, California, where he established a permanent residence.

In 1934, President Franklin D. Roosevelt and his New Deal policies started actively working on an anti-monopoly campaign against the aviation industry.

The timing of this governmental legislation was poor at best for most of the United States and the World was under the black cloud of the Great Depression.

Hamilton started with the “United Aircraft Export Company” as a sales representative, quickly rising to become president of the corporation by 1936.

For example, a deal was set up with BMW to license them to build a number of Pratt & Whitney engines, which was approved by the United States Congress.

And he came back from one trip and in a meeting of the executive committee of our company he said, ‘Don't discount this fellow Hitler.’ ‘To you, he's got a Charlie Chaplin mustache, but whatever he may look on the outside, either he or somebody behind him has a strategic insight and a political foresight that is not available anywhere else in the world that I know of’ ”.

[11] It has also been suggested that Hamilton also tried to convince the United States Congress of the seriousness of doing business with countries like Germany, Japan, and Russia.

Once back in the United States, Hamilton found a different sort of career in the hotel and hospitality business.

[12] However, the attack on Pearl Harbor changed Hamilton's plans and he again went back into the aviation industry to run Hardman aircraft (which made nacelles for the B-17 bombers) in Southern California during World War II, for the nominal salary of a dollar a year.