Thurgood Marshall once said he investigated every race riot in the country from 1940 until he left the NAACP Legal Defense Fund in 1961. Often, the investigations gave the NAACP the opportunity to publicize grave inequalities blacks suffered, often at the hands of law enforcement.

Such was the case in Detroit the summer of 1943. At the time, the city's population swelled with black and white Southerners seeking jobs making wartime munitions. Housing was scarce and blacks faced additional discrimination from employers and police. Starting June 20, 1943, black and white mobs clashed for two days, leaving 34 dead and 1,800 arrested. The majority of those killed and arrested were black.

Marshall's report for the NAACP criticized Detroit police for targeting blacks while ignoring white offenders. Marshall concluded, "This weak-kneed policy of the police commissioner coupled with the anti-Negro attitude of many members of the force helped to make a riot inevitable."

Often arriving in the middle of a race riot, Marshall and other members of the NAACP developed tactics to quell mob violence.

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Marshall: Well, the best one was the Detroit riot. I got there. They started one night, and I got there the next morning. And it was rough. I got on the phone, talking to the department of justice in the morning. They got troops out there. Well, then it sort of simmered down, after they got the troops out there.

The interesting thing was that we were all sure that it was the [Ku Klux] Klan or some organized body that started it, and it was not true. That night, in hot summer - all the riots are usually always when it's hot - but two stories started at approximately the same time. One went through the Negro section, that a white Marine had raped a seven-year-old colored girl, at this park. And the other one was that a Negro had raped a white seven-year-old girl. And they started around the same time.

That made us think. But we never could pin it on anybody. And both sides just went out like that. It was rough, I'm telling you.

The one thing you get out of race riots is that no guilty person ever gets hurt. The innocent people get hurt. And the best example was, in the Detroit riot, a colored lady, businesswoman, way upper middle class, had money. She didn't want any part of the riot. She stayed at her country home in Canada until it had quieted down, and she was sure it was safe and quieted down.

So she came by to see how her store was doing. She had two stores. And she's driving down, what they call the Valley, where the Negroes were, and there were two colored teen-age kids standing on the side - two or three, I don't know how many - and they didn't recognize her, thought she was white. I mean, from her skin she looked just like a white person. And they said something about that white so-and-so, and they threw a small rock, I guess about two inches in diameter or something like that, aiming at the windshield, and it went in at a soft place on the right side of her skull, and killed her.

Now, there's a woman that wanted no part of it. She stayed out as long as she could. And you can get examples like that all the way through. It's the innocent people who get hurt in the riot. I don't know anything that will sober you down like a riot will.

The Harlem riots were much better controlled. We learned in the [Mayor Fiorello] LaGuardia administration about defusing it, and when a riot would break in Harlem, a code number would go out. I don't know what it was. And all policemen, except those who were flat on their back in bed, sick, reported to the 123rd Street Precinct. That's right in the middle of Harlem.

In the meantime, all of the white policemen in Harlem, in the area where the riot's going on, just stand perfectly still, and don't use a weapon, don't use a gun. You just stand there until you're replaced. And the guys looting and everything, they just stand there. And then these guys go out, and these other guys, the colored fellow, taps the white fellow on the shoulder, he gets in the car, and in less than an hour, there are all black cops there. So where's the "race riot"? The race riot's gone. The race riot's gone. Then, Walter White, Roy Wilkins and I would get in radio cars and ride around with loudspeakers, telling them, "Cool it, cool it," you know. And we managed to keep them down pretty well.