John M. Murrin, et al., eds., Liberty Equality Power: A History of the American People, 2nd ed., vol. 1 (Fort Worth: Harcourt Brace, 1999), 457.
Continued rescues and escapes kept matters at a fever pitch for the rest of the decade. In the fall of 1851 a Maryland slave owner and his son accompanied federal marshals to Christiana, Pennsylvania, a Quaker village, where two of the man's slaves had taken refuge. The hunters ran into a fusillade of gunfire from a house where a dozen black men were protecting the fugitives. When the shooting stopped, the slave owner was dead and his son was seriously wounded. Three of the blacks fled to Canada. This time Fillmore sent the marines. They helped marshals arrest 30 black men and a half dozen whites, who were indicted for treason. But the government's case fell apart, and the U.S. attorney dropped charges after a jury acquitted the first defendant, a Quaker.