It should probably be said at the very beginning that while we now know them collectively as the Wright Bros., their fame as aviation pioneers is in its essence the work of Wilbur and only Wilbur. It was he who became fascinated with the notion of flight and only later passed this passion on to his younger brother.

So, how did this passion come about? That is thanks to Otto Lilienthal, the famous German pioneer of gliding. Wilbur was keenly interested in his achievements, but initially, had no desire to replicate them or build upon them. He was more like a fan of a sports team, hoping it does good in the next game, but not willing nor able to go out on the pitch and help them play. However, when Lilienthal died as a result of an accident he suffered while flying his glider, for Wilbur the news “aroused a passive interest which had existed since [his] childhood.”^[1] Perhaps, had Lilienthal not died on that day, the Wright Bros. would never have taken a practical interest in aviation at all.

So the answer to your initial question is: because one of them became fascinated with the notion of flight. Yes, they really wanted to be first. It’s hard to say when Orville got interested in the problem. Goldstone states that,

Orville had little or no input before the first visit to Kitty Hawk in autumn 1900. Wilbur, while he was alive, always publicly spoke of the two of them as a unit and after Wilbur’s death, Orville added himself to incidents in which he took no part. But that, according to Tom Crouch, was merely to assuage Orville’s sensitivity to not being included as an equal in every step of the process.^[1]

You ask about patents. That’s an interesting issue. Before we delve into it, let’s just say that the Wright Bros. applied for one, covering their flying machine, its wing-warping system, and rudder, on March 23, 1903. This patent primarily covered the aspects of controlling the aircraft in flight, which had been perhaps the prime problem that aviation pioneers had had to face. Goldstone suggests that Wilbur managed to wrap his head around the problem thanks to his experience with bicycles, which on a very superficial level are indeed controlled similarly—in order to turn, you don’t just turn, but you also lean to the side (‘roll’).

Now, patents, They had some trouble with the application, so they decided to enlist a professional for help.

two weeks into 1904, they contacted Harry A. Toulmin, an experienced patent attorney in Springfield, Ohio. Toulmin’s initial reply to the “Wright Cycle Co.” was perfunctory. A second letter, on January 19, this time to Wilbur, set his fee at eighty dollars and advised that the patent be sought as a “soaring machine,” not a “flying machine.” If the Wrights wanted to apply for the latter, meaning a machine with a motor, “there will be all possible objections raised, a working model, and a demonstration of the operativeness of the device as a flying machine will be insisted upon, and the matter will probably require our personal attention at Washington. For this kind of work we shall be obliged to charge you, in addition to traveling expenses, our per diem rate of $30 for such time as we shall give to the matter.”^[1]

I you’re interested in how these rates compare to whatever prices, try looking at these spreadsheets.

In reference to subsequent events, Wikipedia in English even has an article titled “Wright brothers patent war.’ What an aptly chosen title that is. While you cannot deny that the Wright Bros. had a pure passion for aviation, Wilbur especially, and they did what they did mainly to satisfy that passion, they were also keen businessmen who had no intention of letting go of the money they believed was rightfully theirs. And what they believed was that they are the fathers of (heavier-than-air) aviation as a whole.

It is widely believed that the war temporarily slowed down the progress of aviation in the US and worldwide. US aviation industry suffered as a whole and in my interpretation only managed to revive itself fully only during World War I. Why?

The application Harry Toulmin filed with the United States Patent Office in March 1904 would set the course of American aviation for the next thirteen years. Rather than simply specify the elements of Wilbur’s wing-warping system as a mechanical construction, Toulmin expanded the notion of wing warping to cover any system where the angle of any device at the wing tips varied the “lateral margins” in opposite directions from the angle of wings at the center.5 Thus Toulmin altered the patent from seeking exclusivity for a device to seeking exclusivity for an idea, the principle of lateral control itself. If such a patent was granted and ratified by the courts, it would apply to configurations that the Wrights themselves had not employed or even conceived of and so virtually no aircraft could subsequently be flown without licensing by Orville and Wilbur, precisely the breadth they were seeking.^[1]

How was than even possible?

in 1898, patent law had undergone a profound change; a new and special category of license called a “pioneer patent” had been created by the Supreme Court. In Westinghouse v. Boyden Power Brake Co., Justice Henry Billings Brown had written that “a patent covering a function never before performed, a wholly novel device, or one of such novelty and importance as to mark a distinct step in the progress of the art . . . is entitled to a broad range of equivalents.” Brown did not find “pioneer patent” in the law—no such designation has ever been stipulated in any American statute. Brown’s ruling was “jurisprudential,” applied or simply created by judges based on their interpretation of either the Constitution or the common law.^[1]

The war proved to be as exhausting as any war would be. It certainly hurt the Wright Bros. severely. They could no longer work on their aircraft as much as they would have liked to. Gradually, their designs became obsolete.

Except for one brief training flight he gave a German pilot in Berlin in June of 1911, Wilbur Wright was not to fly ever again [after the flight on May 25, 1910, when they flew together, for the first and last time], so taken up was he with business matters and acrimonious lawsuits. The Wright Company, from the start, demanded a great deal of time and attention. But it was the interminable patent infringement suits that put the most strain on both brothers. “When we think what we might have accomplished if we had been able to devote this time to experiments,” Wilbur wrote to a friend in France, “we feel very sad, but it is always easier to deal with things than with men, and no one can direct his life entirely as he would choose.”^[2]

Wilbur died soon afterward, in May 1912. It was Orville’s job now to pursue his patent claims. He did so with relative success. Thus, we reach your additional question, “How much money did they make from any patents they developed?” Goldstone again,

[1915] saw the end of the participation of the Wright brothers in the advancement of powered flight. In October . . . Orville Wright left the industry he and his brother had been so responsible for creating. He sold his holdings in the Wright Company, including its patents, to a consortium of Wall Street investors. He was titularly retained as “chief aeronautical engineer” at $25,000 per year, but he had in fact retired [and let me add, he was soon sacked for not doing his work]. With Orville no longer an executive of the Wright Company, changes were made. When the Wright Model K hydroplane and the Model L military scout were introduced in late 1915, stability was achieved by ailerons, not wing warping.

At this point, Orville’s fortune was an estimated 1.5 million dollars.

Notes:

all marked as [1], Lawrence Goldstone, Birdmen: The Wright Brothers, Glenn Curtiss, and the Battle to Control the Skies.

[2], David McCullough, The Wright Brothers.

Sources:

1. Lawrence Goldstone, Birdmen: The Wright Brothers, Glenn Curtiss, and the Battle to Control the Skies, 2014.

2. David McCullough, The Wright Brothers, 2015.