The tradition of having an evergreen tree become a symbol of Christmas goes back past recorded written history.
The Druids in ancient England & Gual and the Romans in Europe both used evergreen branches to decorate their homes and public buildings to celebrate the Winter Solstice. Over the years, these traditions were adopted by Christians, who incorporated them as part of their Christmas holiday celebration.
Trees used specifically to celebrate Christmas are mentioned in the early 1600's in Germany and surrounding countries. The families would set up these trees in a prominent location of their home and decorate them with colored paper, small toys, food, and sometimes candles. As these people moved or immigrated to other countries, they brought this tradition with them.
Through the years many different things were used to decorate Christmas trees. As the world moved into the 1900's, many trees were decorated with strings of popcorn, homemade cards and pictures, cotton to look like snow, candy in all shapes and sizes, and occasionally, fancy store made glass balls and hand blown glass figurines. Candles were sometimes used, but often caused devastating fires, and many different types of candle holders were devised to try to prevent tree fires. Electric tree lights were first used just 3 years after Thomas Edison has his first mass public demonstration of electric lights back in 1879. The early Christmas tree lights were handmade and quite expensive.
Today, Christmas tree ornaments can be found in nearly every size, color, and shape imaginable, and they are used to decorate the millions of Christmas trees used throughout the world.