Final answer:
The question refers to the fluctuation in immigration to the United States from a peak year to 1860, but the provided materials do not include data for 1860. They indicate a decline in immigration from 1900 to the 1940s, a rise until 2009, and a decrease thereafter.
Step-by-step explanation:
The question asks about the changes in immigration levels to the United States from their peak during a given period until 1860. According to the supplied figures, immigration to the U.S. saw various fluctuations starting in 1900. Between 1900 and the 1940s, there was a decline in the number of immigrants, followed by a significant increase through 2009, with a subsequent decrease from 2010 onward. Notably, though, the question's reference period starting from 1860 is not directly addressed in these figures as they begin from 1900.
However, there was a peak in immigration around 1907, and by 2005, immigrants made up a historic high of 14.7 percent of the workforce. This indicates that from the peak in the early 20th century, immigration to the U.S. initially decreased and then rose sharply in later years, although specific statistics directly comparing with the year 1860 are not provided in the reference materials.