After the success of the First Murray League in defending the British Isles from Martian Invasion in 1898, President William McKinley toyed with the idea that it may be necessary for the United States to revive it's own League of Extraordinary Gentlemen.

After McKinley's assassination, incumbent President and adventurer in his own right, Theodore 'Teddy' Roosevelt, fast-tracked these plans and within his first few months in office, had handpicked his own League of heroes and rogues to coincide with his expansion of the US Secret Service. This team was comprised of:

- Irene Norton (née Adler), an opera singer, former enemy of Sherlock Holmes, and one of the great detectives' few foes to have been outsmarted by. Irene had been living peacefully with her husband Godfrey since the end of the so-called 'Scandal in Bohemia' that she had been the center of. Although initially unwilling to join the League, President Roosevelt offered Mrs. Norton a considerable sum of money to act as his League's Wilhelmina Murray surrogate, and to lend her vast cunning and intelligence to his cause.

- John Reid, a former horseback vigilante, who brought enforced law and order on the American frontier during its 'wild west' years. Reid was passed his prime when he was approached for the League, but was still operating along with his Native American subordinate. Reid joined based on the offer that the United States government would pardon him for his civil disobedience as a costumed vigilante (along with 'The Fox', Reid was one of the first so called 'masked heroes').

- Ton-Toh, Reid's right hand man, still loyal to his Anglo ally after decades of crime fighting. T.T. was tremendously good at receiving orders and carrying out plans, and was admired by all who knew him for his fearlessness, chivalry and hard working, unquestioning attitude.

- Agent Tom Sawyer, former explorer, then detective and now the poster boy of the US secret service. Sawyer was an idealistic, but somewhat remissive and exploitative spy, who acted almost as an apprentice to veteran adventurers Roosevelt and Reid, but also occasionally a vexation to them and the other League members, as a cocky, arrogant and inconsiderate attitude often came through in his actions.

- Augustus S.F.X. Van Dusen, the renowned 'Thinking Machine', a detective, an escape artist, and a future ally of Janni Nemo. Van Dusen was an exceptional person both mentally, where he was unmatched in problem solving ability, and socially, where he was a gentleman's gentleman, quick witted and kind. Van Dusen, Mrs. Norton and Mr. Reid often enjoyed games of skill with each other such as Chess and the like, due to their shared admiration for each other's intellect.

This League was vastly more unified than it's predecessor, lacking most of the bickering, infighting, and eventual betrayal that ruined the so-called 'Cowboy League', due mainly to the good working relationship between the members (with Sawyer being the one outlier due to his far younger age than his colleagues). This unity led to a much longer lasting team, and a far less tragic conclusion. Missions undertaken by this League comprise of, but are not limited to:

- Performing numerous covert missions in the Philippine – American War, and many of the numerous 'Banana Wars' of the early 20th century.

- As mentioned in the entry for The Celestial League, confronting numerous times the team formed by The Devil Doctor, including in Shangri-La during 1907.

- Helping test the revolutionary automaton, created as a more advanced successor to the Steam Man of the Prairies, called 'Boilerplate'. They did this by taking the mechanical champion on several of their missions, where his success almost overshadowed that of the Leagues' own.

- Battling numerous 'master criminals' of the era, including the self-christened, foreign mastermind Doctor Death, lesser Devil Doctor imitators Dr. Wu Fang and Dr. Yen Sin, and the Gallic crime syndicate known as 'Les Vampires'.

This League had most of its success in the period prior to the US entry into World War 1 in 1917, when the team ended up being split up by then President Woodrow Wilson to each take charge of different aspects of the war effort. Norton and Van Dusen worked in Intelligence, Reid and T.T. reunited as field commanders, and Sawyer as a Captain in the Marines.

The war took it's toll on the group, with Van Dusen resigning midway through his service after being scarred by the atrocities he saw, leaving instead to join the Nemo family on Lincoln Island.

Reid to was disturbed by the industrialized barbarity he witnessed, as his mounted division he and T.T. led was torn apart by modern weaponry, nearly killing the two. Reid retired from service after the conclusion of the war, and passed away shortly afterwards. T.T. chose to retire too in respect for his fallen friend after said passing.

Only Norton and Sawyer remained in the League, but were estranged from each other after Norton's disgust at the Missouri born Officer's actions as a Captain, in which he led many Men to their deaths while staying far behind them. Sawyer was never punished for these technically war criminal actions, but his friendship with Norton was broken irreparably.

Although the Second American League was over due to the fate of it's members, Norton stayed with the newly formed FBI as a senior advisor post-war, and Sawyer went on to help organize the next American incarnation of The League of Extraordinary Gentlemen.