Answer:
Because he believed that in this way he would be able to end slave labor and racist treatment of blacks in the south.
Step-by-step explanation:
After the Second World War, blacks faced great ostility on the part of the population, mainly in the south, where racism had grown and where there were still hundreds of slave labor in favor of the black population, which was very exploited and was often sanded, beaten and chased by white citizens. Roosevelt, knew that for America to be well regarded, this type of situation would have to end and for that reason, he developed a strategy that passed anti-lynching laws across the country, in addition to passing anti-peonage laws. So he believed that hostility towards white citizens and slave labor that still existed would decrease.