[1] After arriving in America, Lewis got a job as a traveling salesman for the London Printing and Publishing Company which he held for nearly two years until quitting it and moving to Chicago in the spring of 1859.

After working there for almost a year as a grocery store clerk, Lewis grew restless again and began to make plans to head west as part of the Pike's Peak Gold Rush.

A day before he was scheduled to leave Chicago, Lewis encountered an old friend of his who persuaded him to abandon his attempt at prospecting and instead apply for a position with Allan Pinkerton's growing detective agency.

[2] After a brief period of training, Pinkerton assigned Lewis to several surveillance jobs throughout the northeastern United States, and in late 1860 invited him to assist in a more in-depth case in New York.

The two men bonded over their shared European background and abolitionist sympathies, and in 1861 Pinkerton thought highly enough of Lewis to entrust him with investigating a murder in Jackson, Tennessee.

[3] Lewis remained in Jackson for five months, cultivating the appearance of an "English gentleman" which allowed him to earn the trust of secessionist locals who were more willing to talk to a foreigner than a suspected "Yankee."

Lewis made observations of the strength and number of Confederate troops he encountered during his return trip to Chicago, which he relayed to Pinkerton after relocating to the agency's new headquarters in Cincinnati.

Lewis would reprise his role as an English noble touring the countryside, accompanied on his journey by Sam Bridgeman, a fellow Pinkerton operative who would pose as his manservant and carriage driver.

While he waited for Moore's response, Lewis continued to observe rebel movements in and around Charleston, including details of Wise's camp and fortifications at Twomile Creek.

[8] After their return from Charleston, Lewis and Bridgeman spent some time investigating secessionist activity in Baltimore, before being called to Washington DC to rendezvous with the recently relocated Pinkerton.

Lewis raised serious objections to the mission, fearing that the number of deported Confederate sympathizers in the city that knew him to be a federal agent would pose a risk to his cover.

Webster had been confined to his bed by an outbreak of rheumatism and was under close surveillance by members of Richmond's secret police, who had begun to suspect his true identity as a Northern double agent.

[13][14][15] During their meeting, Winder gave no indication of his suspicions that Lewis and Scully might also be Northern agents, and let the two leave after only asking a few questions about their opinions of the Confederacy and reasons for traveling to Richmond.

Due to the jail's light security, the group was able to make it north of the Chickahominy River and almost reached the Northern army's front line before being recaptured by Confederate troops on March 19.

On April 10, two days before his scheduled date of execution, Lewis met with Judge Advocate William Crump and confessed to him the circumstances of his employment to Pinkerton and the reasons for his trip to Richmond.

After currying favor with the captain and writing several letters to Pinkerton in Washington, Lewis and Scully were able to obtain their release in exchange for Confederate prisoners being held by the Union Army.

[23] Lewis returned to Washington and worked as a bailiff at Old Capitol Prison until June 1864, when Colonel Lafayette Baker accepted him back into his reorganized military secret service.

[24] During this time Allan Pinkerton had been working to bring attention to the story of Timothy Webster and in 1884 published The Spy of the Rebellion, in which he presented an embellished account of his agency's activities during the war, including Lewis' trip to Charleston.