Doctorow’s emphasis of story appears to be on inequities in society at the beginning of the twentieth century, and he does so subtly by following unrelated characters of different social status as their paths cross. In this manner, we become acquainted with the characters as they are affected by employment, travel, different factions fighting for civil rights, and each other.
The little boy of the first mentioned family is growing up, and we see an interesting side of him:
In fact he continued the practice not from vanity but because he discovered the mirror as a means of self-duplication. He would gaze at himself until there were two selves facing one another, neither of which could claim to be the real one. The sensation was of being disembodied. He was no longer anything exact as a person.
(…) He believed that statues were one way of transforming humans and in some cases horses. Yet even statues did not remain the same but turned different colors or lost bits and pieces of themselves.
It was evident to him that the world composed and recomposed itself constantly in an endless process of dissatisfaction. (p. 135)
This is a fascinating development when set against the established stories of the magician, Harry Houdini, and the elusive Evelyn Nesbitt who so readily transforms herself to suit whatever situation she faces.
I also find it fascinating in raising the question of time and space as the boy goes about his consideration of the world around him:
But the boy’s eyes saw only the tracks made by the skaters, traces quickly erased of moments past, journey’s taken.
The Lost Children: A Charity Anthology