From infancy to a worldwide phenomena:

                                                       Black Lives Matter Movement

Black lives matter is an ideological and political intervention in a world where black lives are systematically and intentionally targeted for demise.It is an affirmation of  black people's contributions to the society, humanity and their resilience in the face of deadly oppression. BackgroundOnBLM
Black Lives Matter was initiated by Alicia Garza, Patrisse Cullors and Opal Tometi as a means of activating black people's consciousness and making them more aware of their contributions and their value to the society and humanity at large. This Movement was started in 2012 after 17-year-old Trayvon Martin a black teenager was posthumously put on trial for his own murder, and his killer George Zimmerman a white man, was not held accountable for murdering him.  NewsArticle
It was after this sickening incidence that the thought of initiating this kind of movement begun, The co-founders of this movement had realized that racism still existed, and a black man's life does not matter as much as a white man's life.
The movement first started on social media specifically Twitter, it was because of the far reaching effects that Twitter has, that made so many people to know about this movement and follow its course which is to liberate and restore the black lives value across the world not just where the incident actually happened which is Miami Florida.
To prove that black lives still don't matter on the 17th July 2014 in the streets of New York City a police brutality towards a black man named Eric Garner took place the NYPD police claim that the black man sold un-taxed cigarette at the side of the road, the police officer choked Eric and avoided him when he kept on saying he couldn't breathe up until he became unconscious then later died on his way to the hospital. The founders of Black lives matter movement lambasted the New York City mayor Bill de Blasio questioning how could things like this happen under his watch,VillageVoiceArticle 
Even though this movement started as just another Social media campaign, its course has become more than just that, it caught many people's attention even more so it caught the attention of  the most influential celebrities like Samuel L Jackson, Beyonce and Jay Z, Kanye West and John Legend.List Of Celebrities supporting BLM movement.
While the people who are opposing this movement of Black lives matter use the slogan 'all lives matter', the black lives matter movement's defender the US president Barack Obama addressed this issue by giving a speech stating reasons why the movement is called what it is called, he made it crystal clear that the movement's initiators knows that all lives matter, but due to the atrocities, police brutalities and the senseless killings that the black people endure on a daily basis the founders had to choose this kind of name they chose, it wasn't because other race's lives mattered less to them.Obama Defense of BLM.
Donald J. Trump opposes the movement as he contends that what the African-Americans who are supporting this movement do not know exactly what it is they want to achieve by this movement he accuses the protesters of being trouble and seeking for attention he even goes as far as to saying that all lives matter which is the well known slogan used by the opposers of the movement.