No. Many critics who make this claim this point to a single photograph in which an alarm clock was removed from a photo (Lodging Interior - Piegan, volume 6). However, Curtis scholar Herman Cohen Stuart has identified examples of modern western influences in photographs in all twenty volumes, including automobiles, housing, and clothing. It is more likely that Curtis had the clock removed simply because it was visually distracting and was not in keeping with the pictorialist ideals of making timeless photographs. For more about this issue, please see Herman Cohen Stuart, Unraveling Edward S. Curtis's The North American Indian (Cambridge Scholar's Publishing, 2023), and Shamoon Zamir, The Gift of the Face, Portraiture and Time in Edward S. Curtis's The North American Indian (University of North Carolina Press, 2014).

No. According to two of his children who traveled with him after they became young adults, they never saw him use any regalia or objects that weren't offered by the people he photographed. It's true that some regalia appears in his photographs mutliple times or, more rarely, clothing from a particular Native Culture appeared on people from a different culture. It is thought that these were presented by the people Curtis photographed.

Curtis was photographing using a large format view camera. This style of camera, which is still used today, employed a film holder that would be inserted at the back of the camera once the subject was in position. However, the "film" used by Curtis was a glass plate negative. In Curtis's time were produced by Eastman Kodak and had a film speed of ASA 14. Most modern day sheet or roll film used today has a film speed of at least ASA (ISO) of 100 and often more. The result of using this type of film, and all photographers of Curtis's time were using this or something very similar, was that the exposure time was fairly long. It was not possible to simply point and shoot as we would today since the film was too slow. As a result, people had to fix their facial expression for several seconds. In addition, Curtis wanted his portraits to show the dignity of the people he photographed. Their facial expressions often reflected the difficulties they had experienced and their dislike for what had happened to their cultures due to treatment of the federal government and the incursions of white settlers on what was once their lands.

This is the result of the orthochromatic film that was commonly used until the 1920s. This film is sensitive mostly to the blue end of the light spectrum and not sensitive to red wavelengths. The result is that anyone who had darker skin tones was rendered as very dark when printed. There are two types of black and white film, orthochromatic film and panchromatic. The difference in the two films for this question is their light sensitivity. One benefit of using this type of film emulsion is a red safelight may be used in the dark room for loading the film and for processing the film as well. Panchromatic film is sensitive to a much wider light spectrum and renders reddish things in a more accurate way. Unfortunately, the film must be loaded and processed in total darkness. For a more detailed explanation see here: https://filmphotographyproject.com/content/howto/2018/07/panchromatic-orthochromatic-film/

The North American Indian project cost the current-day equivalent of approximately $25 million to complete. Although he received substantial funding from J. P. Morgan, as part of that agreement he had to raise all the money to publish, distribute, and sell the publications. Curtis was so obsessed with the scope and quality of the books that he regularly spent more than he was able to raise. He worked without a salary for most of the 24 years it took to complete the work, and he never received any money from the sale of the books..By the time he completed the project in 1930, he was financially depleted and in debt from several personal loans he had taken out to be able to complete his work. For more about the extraordinary measures that Curtis took to fund his project, please see the study "Duty Bound to Finish: Edward S. Curtis and His Quest for Money to Complete The North American Indian." ​

This number has been widely reported, but it is usually offered without any context. The number of documented photographs from the project is significantly less, probably closer to 5,000. It seems more likely that Curtis made 40,000 exposures during the 24+ years he worked on the project, but he deemed many these not work keeping. He also might have reused some of the glass plates in the early years when he was hand-coating the emulsions. While the 40,000 number seems enormous, it is not out of line with the known output of other photographers during the early 20th century. For example, the Washington State Historical Society holds 60,000 photographs created by Edward's brother, Asahel, who died nine years before his brother.

Curtis is said to have made as many as 10,000 recordings of voices, songs, dances, and events by using the wax phonograph cylinder process. While this type of recording was the best that was available at the time, they had one major flaw: every time they were played, the medium on which they were recorded degraded. In addition, the wax itself weakened over time. Curtis did not have the money to transfer the recordings to more stable technology, and, as a result, most of his recordings have been lost over time. Only 279 of the original wax cylinders are known to survive at this time. Fortunately, they are well preserved at the Indiana University Archives of Traditional Music.

By the time the last volume of The North American Indian was published in 1930, Curtis was financially and physically exhausted. He had spent nearly 30 years on his project, and unforeseen circumstances such as World War I and the stock market crash of 1929 diverted most American attention away from the plight of Native Peoples. After 1920, Curtis lived in Los Angeles with his daughter and her husband, and for a while, he worked making film stills for Hollywood studios. He became fascinated with gold and was writing a book about the lure of gold when he died at the home of his daughter in 1952. Sadly, he didn't live to see the remarkable renewal in his work that began in the 1970s.