James was a merchant based in Ware, Hertfordshire.
In 1807 Britain was at war with France. How did James die in France aged 34? In today's money his cash legacies to his family were roughly £280,000. (See will below).

This is the last will and testament of me James Usborne of Ware in the county of Hertfordshire, Merchant, which I make, publish and declare.  I give and bequeath unto my mother the sum of one thousand pounds.  I give and bequeath unto my sister Elizabeth, two thousand pounds.  I give and bequeath unto my sister Sophia Usborne the sum of two thousand pounds and it is my wish if my said mother or any of my said sisters shall happen to die before me then the said legacy or legacies hereinbefore given to her or them I give and bequeath to my brother William Usborne so dying shall go unto and be equally divided between and among the survivors of them.  I give and bequeath to my brother William Usborne the sum of one thousand pounds but if he shall die before them I give the sum unto and amongst all his children, which shall be living at my death, in equal shares.  I give and bequeath to my brother Thomas Usborne the sum of one thousand pounds all which legacies it is my wish shall be paid within nine calendar months next after my death.  I give, devise and bequeath all the rest and residue of my estate and effects whatsoever unto my said mother Elizabeth Usborne my brothers John Usborne, Thomas Usborne and Henry Usborne and my said sisters Elizabeth Usborne, Jane Usborne and Sophia Usborne or such of them as shall be living at my death in equal shares to take as tenants in common and not as joint tenants.  I appoint my said brothers John Usborne and Thomas Usborne executors of this my last will.  In witness whereof I have hereunto set my hand and seal this first day of February in the year of our lord one thousand eight hundred and two, James Usborne.