The shirt on his back by Barbara Hambly

Benjamin January is a free man of color in 1830s New Orleans.  When the book opens, Benjamin's family is down to their last two dollars and fifty cents.  The local banks have failed and Benjamin is unable to earn money as a musician because no-one can afford to host a ball or pay for piano lessons.  Enter Benjamin's friend, Lieutenant Abishag Shaw of the New Orleans police.  Shaw's just learned that his younger brother was murdered out west and wants Benjamin to go with him to find his brother's killer.  Once again, Benjamin risks losing his freedom to help out a friend. They travel up the river to join the annual fur trappers rendezvous.  Hambly manages to mix historical detail with a very engrossing adventure story. I couldn't put it down! 250 pages