Historians estimate the traditions and rituals associated with Día de los Muertos ("Day of the Dead") date back 2,500 to 3,000 years to the indigenous cultures of Mexico. While these rituals have been taking place for thousands of years, the first outsiders to see them first hand would have been the Spanish Conquistadors who landed in Central America only some 500 years ago. During these early encounters the Conquistadors might have been met with actual skulls, as during the pre-Hispanic era it was common for skulls to be kept as trophies that would be displayed during rituals symbolizing death and rebirth.
The Day of the Dead festivals and rituals originally took place in the ninth month of the Aztec calendar, which translates to about the beginning of August. These original festivities were celebrated for the entire month and were dedicated to the goddess Mictecacihuatl - the Lady of the Dead. In modern times this Lady of the Dead has come to be symbolized by the Catrina ("the skeleton of a high society woman"). The original month long festivities are now celebrated on the Catholic All Saints Day and All Souls Day at the beginning of November.
November 1st, in most regions of Mexico, honors the passing of infants and children and is simply known as Día de los Inocentes ("Day of the Innocents"). November 2nd is when the passing of adults is celebrated and is known as Día de los Muertos ("Day of the Dead"). On these days, family members and friends travel to cemeteries to be with the souls of the deceased and pay homage to them with colorful alters, food, and beverage. To encourage visits from the souls of the deceased pictures and other items from the past are often used in these ceremonies. Family and friends may also tell stories, generally humorous or lighthearted, of the deceased to encourage visits by their souls.
To accompany these traditions in the cemetery, many families build altars in their homes to pay homage to the deceased. These altars generally have many of the same ofrendas ("offerings") that are found at the cemetery but may also include more permanent objects such as decorative Christian crosses, pictures of the Virgin of Guadalupe, candles, and Catrina figurines.
Even though the Day of the Dead is generally associated with Mexico, and is a Mexican tradition, it has spread and is currently celebrated throughout the United States, Latin America, Europe, Asia, and Oceania. Some of the noted celebrations within the United States include Los Angeles, San Francisco, Missoula, Montana, and various parts of Texas and Arizona. Communities with large Mexican populations typically have celebrations similar to those held in Mexico.
Regardless of where these celebrations take place or the type of ofrenda ("offering"), the Day of the Dead will always stay true to its roots as a celebration of the cycle of life and death.