Prior to 1737, Our Lady of Guadalupe was one of three primary images of Our Lady venerated in Mexico. While many venerated her, the unique image did not hold widespread devotion.
Then in 1736 a devastating epidemic swept across the nation, as detailed by Vernon Quinn in the 1924 book Beautiful Mexico: "an epidemic of yellow fever ravaged the country causing in Mexico City alone fifty thousand deaths."
In March 1737 the city council petitioned the local archbishop to declare Our Lady of Guadalupe patron of the city. He agreed and scheduled a large procession and celebration in May, imploring Our Lady of Guadalupe to spare their city and surrounding area from the epidemic.
According to Jennifer Hughes in her book, Biography of a Mexican Crucifix, this act of faith by the Mexican people helped turn the tide of the epidemic and solidified Our Lady of Guadalupe's role in Mexican culture.
In 1746 her patronage was extended to all the territories of New Spain and in 1754 Pope Benedict XIV instituted a feast and Mass for December 12.
The end of the epidemic was seen by the local people as due to her miraculous intercession and ever since the Mexican people have had a strong devotion to Our Lady of Guadalupe.
