Benjamin Banneker was a scientist, inventor, writer, farmer, engineer, surveyor, city planner, astronomer, mathematician, author, and social critic.  Among Banneker's talents, he had a remarkable memory.  After the Frenchman who was hired to design the capital quit and left with the plans, Banneker recreated the plans from memory within two days.  Also, from 1792 to 1802, Banneker published and computed all the calculations for an annual Farmer's Almanac that brought him notoriety in America, England, and France.  Banneker was also a social critic.  In an attempt to promote change, he sent a copy of his Almanac to Thomas Jefferson.  He enclosed a letter in which he wrote about the inconsistency of Jefferson's position on the equality of all men while at the same time owning slaves.