Add a footnote citation outside of plot area in R?

Question

I\'d like to add a footnote citation to my 3-panel facet grid plot produced in R. It\'s a footnote to credit the data source. I\'d ideally like to have it below and external t

Answer 1

Adding to the answer of Brandon Bertelsen: if you want to have the caption in the left corner, add

theme(plot.caption = element_text(hjust = 0))