July 13
Southern Tenant Farmers' Union organized in Tyronza, Ark. - 1934

Detroit newspaper workers begin 19-month strike against Gannett, Knight-Ridder - 1995
And this: July 13, 1995 - Newspaper workers began a strike against The Detroit News and Detroit Free Press, owned by media giants Gannett and Knight-Ridder. Hundreds of workers were eventually locked out in the protracted struggle.
Labor history found here:
http://www.unionist.com/today-in-labor-history & here:
http://www.workdayminnesota.org/index.php?history_9_07_13_2011