When Oliver Cromwell and his Puritans took control of England in 1645, they outlawed Christmas because they saw it as decadent revelry. The Pilgrims of New England felt the same way. They also waged war on Christmas — it was banned in Boston from 1659 to 1681.
And, where did the date for Christmas come from anyway:
In the Western world, the birthday of Jesus Christ has been celebrated on December 25th since AD 354, replacing an earlier date of January 6th. The Christians had by then appropriated many pagan festivals and traditions of the season, that were practiced in many parts of the Middle East and Europe, as a means of stamping them out. . . . Saints Days have also contributed to our Christmas celebrations. A prominent figure in today's Christmas is Saint Nicholas who for centuries has been honored on December 6th. He was one of the forerunners of Santa Claus. . . . Celebrating Christmas has been controversial since its inception. Since numerous festivities found their roots in pagan practices, they were greatly frowned upon by conservatives within the Church. The feasting, gift-giving and frequent excesses presented a drastic contrast with the simplicity of the Nativity, and many people throughout the centuries and into the present, condemn such practices as being contrary to the true spirit of Christmas.
The earliest English reference to December 25th as Christmas Day did not come until 1043.
Details of the pagan festivals appropriated can be found in the link above. According to "Christmas in America: A History," by Penne L. Restad (1996), at page 4, in the 200s Chistian scholars claimed various dates for the birth of their namesake including May 20, April 19, November 18 and March 28.
Wikipedia notes some of the American history of Christmas:
Christmas fell out of favor in the United States after the American Revolution, when it was considered an English custom. . . . Interest in Christmas in America was revived in the 1820s by several short stories by Washington Irving appearing in his The Sketch Book of Geoffrey Crayon and "Old Christmas", and by Clement Clarke Moore's 1822 poem A Visit From St. Nicholas (popularly known by its first line: Twas the Night Before Christmas). Irving's stories depicted harmonious warm-hearted holiday traditions he claimed to have observed in England. Although some argue that Irving invented the traditions he describes, they were widely imitated by his American readers. The poem A Visit from Saint Nicholas popularized the tradition of exchanging gifts and seasonal Christmas shopping began to assume economic importance. In her 1850 book "The First Christmas in New England", Harriet Beecher Stowe wrote a character who complained that the true meaning of Christmas was being lost in a shopping spree. Christmas was declared a United States Federal holiday in 1870, signed into law by President Ulysses S. Grant.
An English actress in America Fanny Kemble observed in 1832 (Restad at 17):
Christmas Day is no religious day and hardly a holiday with them. New-year's day is perhaps a little, but only a little more so. For Twelfth-day it is unknown; and the household private festivals of birthdays are almost universally passed by unsevered from the rest of the toilsome days devoted to the curse of labor.
New England Sufferagist Elizabeth Cady Stanton didn't recall Christmas as a great festival of her youth. (Restad at 17) Many Calvinist New Englanders took days off for election day and Harvard's Commencement Day (in July), but not Christmas. (Restad at 19).
The Advent Calendar tradition is roughly 150 years old.
The Advent Calendar has been around for more than 150 years and becomes more popular every year.
The origin of the calendar, like so many of our Christmas traditions, started in Germany back in the 19th century. Different methods of counting down the days to the celebration of Christmas were used. . . . The first printed calendar was produced by Gerhard Lang in Germany. When he was a child, his mother attached little candies to a piece of cardboard and each day Gerhard would take one off. His first (printed) calendar consisted of miniature colored pictures that would be attached to a piece of cardboard each day in December. Later Advent calendars were made with little doors to open on each day.
The child might find a small piece of candy, a Christmas picture, a religious picture or a bible verse.
The German calendars were sold until World War II, at which time production was stopped due to the war shortages. After the war, the production of calendars resumed in 1946 by Richard Selmer. Selmer credits President Eisenhower with helping the tradition grow in the United States during his term of office. A newspaper article at the time showed the Eisenhower grandchildren with The Little Town Advent calendar.
The modern relevance of advent seems to be waning. Secular Americans don't have a context for it. Non-liturgical Protestants, who eventually succumbed to peer pressure to recognize and embrace Christmas itself, rarely went on to adopt the nearby seasons of the liturgical calendar -- Advent, Epiphany and Lent, as well. The ranks of liturgical Christians are ebbing. Also, almost all of the mainline Christian denominations have shifted their worship practices to some extent in the direction of those of the Evangelicals over the past few decades.