Don't mourn, organize!

is an expression, abridged from a statement by labor activist and songwriter Joe Hill near the time of his death.

Hill followed that telegram with another: "Could you arrange to have my body hauled to the state line to be buried?

"[1] In 1915, Hill was convicted and executed for the murder of John and Arling Morrison a year prior; he denied having committed the murders but, for reasons that remain a source of speculation, was unwilling to give an alibi during his trial.

The phrase is popular enough in its association with Joe Hill and the labour movement that it was the title of a music compilation made in 1990 and released by Smithsonian Folkways.

[2] In 2017, activists used the phrase to motivate protest against President Donald Trump and his administration.