Finally, the date was set for Collins's departure. On 18 July 1873, he wrote to William Tindell that he would be leaving for New York on 13 September and that, before departure, he felt it necessary to execute a new will for the security of his dependents. With Caroline Graves, his ‘housekeeper’ and her daughter Harriet, and with Martha Rudd (his morganatic wife) and their two daughters, his responsibilities were many. Collins maintained these long-term relationships concurrently. Caroline and Harriet lived with Collins from about 1858 until his death in 1889. During a brief break in 1868 when Caroline left to marry someone else, Collins set up housekeeping with Martha Rudd, a woman more than twenty years his junior. Although the two never married, they assumed the name of Dawson and eventually had three children together. In addition, he was not in the best of health. He suffered from chronic ‘rheumatic gout’ and had been told he had a weak heart. Two days before his departure, he signed a new will, leaving half of his estate to Caroline and Harriet for their lifetimes and the remainder to Martha and their children.

The United States that Collins proposed to visit had a population of about forty million in 1873, spread across thirty-seven states and ten territories. The transcontinental railroad, completed in 1869, linked California with the east coast, and more than 60,000 miles of rail lines criss-crossed the country. As settlers sought new opportunities in the western territories, the United States Army continued to relentlessly pursue the Native American tribes; Custer's Last Stand was to occur three years later in 1876.

Following the end of the Civil War in 1865, the United States witnessed dramatic economic growth and the beginning of reconciliation between the Union North and the Confederate South. Railroad magnates, oilmen and financiers were amassing enormous wealth and the ‘Gilded Age’ was commencing. Greed and corruption riddled American politics, particularly during the administration of Ulysses S. Grant, the venerated Civil War general who was elected to his second term as President in November 1872.