There Is a River: The Black Struggle for Freedom in America, by Vincent Harding. New York: Harcourt Brace Jovanovich. $19.95. A century before Rosa Parks refused to give up her bus seat to a white man in Montgomery, Ala., Elizabeth Jennings took a similar stand against racial discrimination on the horse-drawn railway system in New York. The arrest of Rosa Parks brought on Martin Luther King Jr.'s bus boycott and thus virtually launched the 20th century's vividly remembered civil rights movement. The act of Elizabeth Jennings, which helped bring the end of segregation on New York's public transport, is generally forgotten.
But in his new book historian Vincent Harding records this and many other examples of courage in order to remind today's generation that black people have been conducting a civil rights movement ever since they were first shipped to America as slaves. In doing so he eloquently challenges such myths as black passivity, acceptance of dependency, and reliance on liberation by others.
As a black man himself, Professor Harding immediately establishes a tone of closeness and advocacy, as he refers to ''our'' experience of uprooting from Africa and subjugation in America. He does not spare the slaveholders. Yet, as he follows the struggling river of freedom up through the Civil War, he sees that the problem goes beyond them and their legacy of discrimination; it goes to their overt or tacit support by a government and society departing from its highest principles. He evaluates individuals and groups according to whether they grasp the broader picture.
It is as if Dr. Harding were continuing with historical figures the encounters with contemporaries that he was known for during the latter-day civil rights movement. In the late 1960s, for example, when he was head of the history department at Atlanta's Spelman College, he challenged a gathering of black churchmen with questions like: ''What reason is behind our pilgrimage in this land?'' and ''How do you face a nation which says your people have gone too far when we know that the real struggle has just begun?''
Not surprisingly, the present book's endorsers include scholars of the left. The author celebrates the radical voices and actions of the past, those who were ''ready to die in many, many ways,'' to use a phrase from his remarks to the churchmen. He cites gulfs between black abolitionists, for instance, and even their most well-meaning white counterparts. He finds the celebrated Frederick Douglass a sometimes faltering partisan of his people. He stresses the gap between Lincoln's lesser-known racial attitudes and his image of the Great Emancipator. He notes rebellious acts of violence by slaves and freedmen to underscore that black people were capable of unflinching resistance to oppression like the colonists of old.
Yet, for all the justified outrage of men denied all human rights and decency , there is a risk of confusing militant self-defense and marauding vengeance. Not everyone in these pages can make the case of the black Union soldier when he meets the mistress of the plantation where he had been a slave:
''She said, 'you remember when you were sick and I had to bring you to the house and nurse you?' and I told her, 'Yes'm, I remember.' And she said, 'and now you are fighting me!' I said 'No'm, I ain't fighting you, I'm fighting to get free.' ''
Not fighting you but fighting to get free. This was the tone that gave such strength to the crusade of Martin Luther King, whose firming up of his doctrine of nonviolence is described in Howell Raines's ''My Soul Is Rested: Movement Days in the Deep South Remembered,'' a volume of reminiscences by those who would surely figure in a future historian's book on black struggle.
The struggle is not over, as Martin Luther King Sr.'s autobiography, ''Daddy King,'' confirmed. But his recognition of power in the renunciation of hate is an example of how the river can flow on without the bloody currents of that past which Professor Harding so feelingly and skillfully memorializes in this inspiring book.