A year after the new fugitive slave law hit the North, a remarkable incident of resistance burst forth in the border region of southern Pennsylvania. William Parker, an escaped slave, gathered an armed band of blacks against a posse led by a Maryland slaveowner. The blacks were aided by Quakers and other whites who approved the goal but not the means, so to speak. From a stone house Parker's group held off the slavers. The confrontation seems almost serene and sometimes comic, compared with latterday assaults against ghetto blacks. From the window the question of property was debated with the befuddled Marylanders. Parker's young wife blew a horn to rally reinforcements as the marshal's son fired at her from a peach tree. Gorsuch, the slaveowner, was killed. The episode, called a ""riot"" by much of the press, gave rise to ""a local reign of terror."" A treason trial, well and lengthily described here, was cooked up against a batch of whites and blacks. Thaddeus Stevens served as a defense counsel. Parker and his family reached Canada -- ""a noble nigger,"" as even Gorsuch's son conceded. Apart from Katz's tendency to make a fetish of ""armed black resistance,"" he has brought in the surrounding words of Frederick Douglass, Walt Whitman, and the rhetoricians of ""preserving the Union"" at the slaves' expense. Parker himself isn't as vivid as a John Brown, but the potential seems to be there.