The AEA disbanded in 1909, and Curtiss formed the Herring-Curtiss Company with Augustus Herring. Its first customer was the Aeronautic Society of New York. Curtiss delivered his first plane to them, the Curtiss No. 1, built to their specifications, on May 29, 1909. When the Herring partnership split up, Curtiss founded the Curtiss Exhibition Company, the Curtiss Aeroplane Company in December 1911 in Hammondsport, New York, and the Curtiss Motor Company.

The Curtiss 1911 Model D was the second military airplane purchased by the U.S. Army Signal Corps. It was known as Signal Corps Airplane No. 2

In 1910, Curtiss set up shop in San Diego and taught the first naval aviators to fly. That year, he introduced the Model D biplane, which had ailerons mounted between the wings. Curtiss, in cooperation with the Navy, developed a system for takeoff and landing aboard a naval vessel, essentially the first aircraft carrier. On November 14, 1910, a Model D Curtiss plane, piloted by Eugene Ely, made the first takeoff from a ship—the USS Birmingham. On January 18, 1911, Ely landed on the deck of the USS Pennsylvania. A month later Curtiss himself took off from water and landed near the Pennsylvania flying a tractor seaplane.

Curtiss also worked on developing the seaplane, basically a land plane with floats instead of wheeled landing gear. His first seaplane, based on the Model D was manoeuvrable, light, and relatively fast, and was the most widely built type of plane in the United States before World War I.

In February 1911, Curtiss introduced the Triad seaplane, which had both wheels and floats. It was the world's first successful amphibian and became the prototype of later, larger craft. The Triad A-1 first flew on July 1, 1911, and became the first Navy airplane. In November 1912, it performed the first successful catapult launch of a seaplane from an anchored barge. The Triad was sold to the British, Russian, German and Japanese navies in 1912, and Japanese naval aviation was founded with the purchase of three Curtiss Triads. In 1912, Curtiss won the Robert Collier Trophy for his development of the seaplane.

On March 31, 1911, the U.S. government appropriated its first funds for aircraft and purchased three planes from Curtiss and two from the Wright brothers. In the next three years, the Navy bought 13 more Curtiss planes that could be used on floats. A Curtiss seaplane climbed to 6,200 feet (1,890 meters) on June 13, 1913, setting an American seaplane altitude record.

In the meantime, Curtiss had begun working on the flying boat—an aircraft with a large central hull that rested in the water. He realized that water produced a lot of drag on a hull. After trying several designs, his engineers discovered the stepped hydrofoil hull. The hull would produce lift as it moved through the water. When it raised itself enough to expose the step, drag abruptly decreased, and the hull quickly rose more to glide on a small area of the step. The pilot could easily sense these actions. The quick rise and increase in speed told him that his craft was ready for takeoff.

In January 1912, Curtiss debuted his first successful flying boat, The Flying Fish, which incorporated the stepped hull. The Curtiss F two-seat biplane flying boat became the Army's first flying boat and was also used by the Navy. During World War I, it was the primary training flying boat. During the war, Curtiss received so many orders for flying boats that he hired Boeing and Loughead (later renamed "Lockheed") to build them to his specifications.

In 1914, Curtiss built the America, the first two-engine flying boat. To commemorate 100 years of peace between the United States and England (following the War of 1812), the America was to fly the Atlantic with a crew of two—an American and an Englishman. Navy destroyers were to be stationed every 100 miles (161 kilometres) along the route for safety. But World War I began and the flight was cancelled. Britain bought the airplane and 20 similar models that were either modified or manufactured in England, marking the beginning of England's flying-boat industry. The aircraft were used extensively for antisubmarine patrol.

During World War I, Curtiss produced thousands of Curtiss OX-5 engines—a water-cooled V-8 with 90 horsepower (67 kilowatts). The company produced 10,000 aircraft during World War I, more than 100 in a single week. Its most famous product, however, was the JN series of military training aircraft, known as "Jennys." These planes were the most widely mass-produced U.S. aircraft in the first 15 years of aviation history. Large numbers of the Curtiss JN-4 Jenny were manufactured between 1916 and 1927 and used by Canada, Great Britain, and the United States. It continued as a barnstorming airplane well into the 1930s.

The N-9 was the seaplane version. It had a heavier engine than the Jenny to compensate for the extra weight of the floats and an upper wing that was some 10 feet (3 meters) longer than the lower one. Developed in late 1916, it served in U.S. Army and Navy flying schools until 1927.

As business expanded, the Hammondsport factory became unable to fill all the orders. Curtiss extended its operation to Buffalo, where it rented the site of the company that had supplied Curtiss with his first bicycle engine years before. Curtiss also opened a new plant in Toronto. The quarters in Buffalo quickly became inadequate, and a new 120,000-square-foot (1,115-square-meter) building was constructed that became the company headquarters. Soon after, a new plant that sprawled over 72 more acres was added.

In 1916, the Curtiss Aeroplane & Motor Company, Ltd. went public with Curtiss as president. By that time Curtiss had become the world's largest aviation company, employing as many as 18,000 at Buffalo and 3,000 at Hammondsport.

In 1917, Curtiss began collaborating with the Navy to build a flying boat that could cross the Atlantic and join naval war operations quickly. The team came up with a wide-span biplane that could accommodate a crew of five. It was designated the N-C (for Navy-Curtiss), and the Navy ordered four. Although the war ended before all the craft were built, the Navy decided to proceed with the project. In May 1919, a four-plane fleet attempted the first transatlantic flight. Only one, the NC-4, successfully flew, by stages, from Rockaway, New York, to Lisbon, Portugal. This was the first successful airplane crossing of the Atlantic.

After the war, Curtiss, fell on hard times. In August 1920, the company was forced into receivership. Clement Keys, a Canadian financier, obtained funds to manage the company's debt and led it again to sound financial status. The Buffalo facility became the major facility, and the company remained the largest U.S. aircraft company through the 1920s. Its racing planes, including the CR-1 and CR-3, won several competitions. The CR-3 won the 1923 Schneider Cup race, the first time it was won by a U.S. plane. The Americans again won in 1925 with a Curtiss R3C-2, piloted by Jimmy Doolittle, an Army pilot who would become famous during World War II. Curtiss planes also competed in the Pulitzer Trophy and Gordon Bennett Cup races. The P-1, first in a long line of Hawk pursuit planes for the Army, was ordered in September 1925, and the company built a line a observation airplanes as well.

The company also continued building aero engines. Its most significant was the D-12. It was equipped with a propeller that could rotate at a higher speed than conventional propellers and which allowed the engine to use its full power. The D-12 powered the Curtiss planes that won the first four places in the 1921 Pulitzer competition and the Schneider Cup races in 1923. The D-12 would prove to be the model for in-line engines worldwide from that time.

In 1929, shortly before Curtiss died, the Curtiss Aeroplane & Motor Company, Ltd., merged with the Wright Aeronautical Corporation to form the Curtiss-Wright Corporation.