I have Horatio Philanzo Allen and twin Augustus Lovanzo Allen, born August 23 1809 in Fort Plain, Montgomery County, New York. They both attended collage at Union Collage in, Schenectady, New York. They were admitted to practice law in Albany, in 1835.
Horatio Philanzo Allen, settled in Buffalo, New York, and formed a partenership with LeGrand Marvin, then in 1839, moved to the city of New York and opened a practice there.
September 2 1840, he marrird Hannah Jarvis Ingersoll, born October 14 1820, daughter of Dr. John J. Ingersoll. They had 4 children:  Augustus Henry Allen, b. August 6 1841.  Gertrude Ingersoll Allen b. October 10 1844.  Elizabeth Seymour Allen b. July 12 1848.  Florence Allen b. May 8 1852. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Horatio Philanzo Allen's parents were; Nathan Allen & Mary Putnam [her parents, Aaron Putnam & Rebecca Hall] The children of Nathan Allen & Mary Putnam; (1) Mary Putnam Allen (2) Nathan Prescott Allen [my ggg-grandfather] (3) Lucius Henry Allen (4) Eliza Rebecca Allen (5) Aaron Putnam Allen (6) William Rufus Allen (7) Sophia Mehitable Allen (8) Horatio Philanzo Allen (9) Augustus Lovanzo Allen
I got some of the above information from a book that was written by one of the Allen brothers in about 1895, but haven't figured out which one yet. Teri