We have much to remember and be thankful for during Black History Month, but there’s also much to mourn. Today would’ve been Trayvon Martin‘s 20th birthday. The 17-year-old Fla. teen was gunned down by neighborhood watchman George Zimmerman in 2012. The senseless deaths of unarmed Black men haven’t stopped: Michael Brown, Eric Garner, and Tamir Rice were all killed in 2014 alone. But public awareness is sky high and our patience has run thin.

People are reflecting on the national and international outcry against police brutality and the festering racial biases that continue to thrive in America. Below, we chronicle the time from Trayvon Martin’s murder to the evolution of #BlackLivesMatters. These are moments that will undoubtedly go down in history.