As with your previous question, this one appears to be taken from For the Record, edited by Shi and Mayer. My answer comes from the excerpt of the New York Times article that is listed as “From The Late Convention of Colored Men” in that compilation of primary sources.
According to the authors of this message, there were two main reasons why the freed blacks needed protection. First, the African Americans point out a number of times that they helped the Union very much during the Civil War. They say that the Union called on them for help and that they responded eagerly. Second, they argue that President Johnson’s Reconstruction program has given power back to whites who are not truly loyal to the Union. They say that these whites have loyalty to the federal government that is only “lip deep.” They argue that the whites will, as soon as they can, make laws that will make the situation of African Americans as bad as it was under slavery. The whites will do this because they hate the blacks for having helped the Union.
All in all, the African Americans who wrote the message say, they are like “sheep in the midst of wolves.” They have no way to protect themselves from the white Southerners. They say they need and deserve protection since they are being persecuted for having helped the North.