The demonstration, organised by the civil rights group Black Lives Matter, took place days after police killed Alton Sterling in Baton Rouge. A video showed two white police officers holding him down and shooting him. Police said they had received a report an armed man was making threats.
Other notable figures online to share the image include Calestous Juma, a Kenyan-born professor at the John F Kennedy School of Government, who was once named among the 100 most influential Africans.
British-Indian novelist Hari Kunzru praised the "grace under pressure" shown by the woman in the photo.
Bachman said he was unaware of the praise he was getting until his father called him, a few hours later.
So how does he feel?
"I feel very humble to capture an image that tells the story of what has been happening here in Baton Rouge.
"The woman did not show any aggression toward the police. I feel it is very representative of the peaceful demonstrations that have taken place here. People are very angry and have gone through a tremendous amount of pain; but they have not turned to violence."
He is still in Baton Rouge, covering the events there.
The incident was also captured from another angle by Associated Press photographer Max Becherer.
AP reported that the woman in the photograph was grabbed by officers after refusing to move off the road.
The protests were not entirely peaceful - Louisiana's The Advocate newspaper said 102 people were arrested, with eight guns seized. One police officer lost several teeth after being hit by a projectile, it said.
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