John Brown, a zealous abolitionist, led an attack on the federal arsenal at Harper's Ferry in Virginia. He was joined by three of his sons and about 20 other men. He expected slaves to join in the uprising, and as stated in March, "he had the weapons - about a thousand spears, wagon loads of Sharps rifles and pistols - waiting for them," but the slaves did materialize (159). Instead, two of his sons and several of his followers were killed, and Brown was injured in the attack and taken prisoner - later to be hanged for his crimes. Some saw his as a martyr, others as a traitor.
Brown becomes involved with March and other citizens in Concord prior to this when he comes to lecture at a Concord church and seek support for his cause. March and his wife attend the lecture, where "Brown proclaimed that he had no doubt it would be right, in opposition to slavery, not only to accept a violent death, but also to kill" (120). Though March is skeptical of anyone who has "no doubts" about anything, he sees how positively his wife reponds to Brown's words and feels compelled to do something.
The Marches later invite Brown to their home, where March - largely in an effort to win his wife's approval - offers Brown the majority of his fortune in support of his Adirondack project, which Brown says will help indigent blacks become landowners. However, March later learns that the land Brown bought was worthless and that most of the money he had collected was actually redirected to purchase the weapons used in the attack on Harper's Ferry. In realizing this, March reflects:
I had absolved Brown, long ago, for the loss of my fortune; I had schooled myself to look back on the episode without bitterness or blame. But I had advanced him money to free human beings, not to slaughter them. I knew I could not forgive, if my innocent ties to Brown implicated me in such killings, and proved the means of undoing the blessed bonds of my family (160).
The family never financially recovers from this loss, and March - as well as many other Concord citizens - is left to worry if his unsought role in this attack will ever be revealed.
My answer is the answer above, but apparently the links didn't work the first time, so here they are again.