Since before Christmas existed, people used plants that stay green all year to decorate their homes in the winter. Hanging evergreen boughs over a door was a reminder of springtime during the cold, dark winter. But it wasn’t until the 16th century in Germany that Christians started using trees as decorations around Christmas. German settlers in Pennsylvania brought the first Christmas trees to America in the late 1700s, but they weren’t common until after 1834. That’s when Prince Albert, the German husband of Britain’s Queen Victoria, first brought a Christmas tree to Windsor Castle. The royal family was very popular, so many people wanted to have a Christmas tree like the royals — even Americans! The idea stuck, and people have decorated trees at Christmas ever since.
Answer provided by Yahooligans.com