1. In 1776, Father Junipero Serra celebrated the first Christmas mass in California at Mission San Diego de Alcala. This was the first Christian religious celebration in California.

2. In 1849, the first Christmas tree in California was erected by a German immigrant named August Lang in his San Francisco home. This event marked the beginning of the Christmas tree tradition in California.

3. In 1869, the United States completed the first transcontinental railroad in Utah, which connected California to the rest of the country. This enabled people to travel between California and other states more easily, allowing them to celebrate Christmas with family and friends who lived far away.

4. In 1939, snow fell on Christmas Day in Los Angeles. This was the only time in recorded history that Los Angeles has had a white Christmas.

5. In 1955, Disneyland opened its gates for the first time on Christmas Day. The theme park was decorated for the holiday season and included a parade and special Christmas-themed shows. Disneyland has been a popular destination for families to celebrate Christmas ever since.