Early History
From 1838 to 1861, inventors could file patent applications on improvements to their inventions. These were published as "additional improvement patents" and were given numbers preceded by "A.I.". About 300 of these patents were issued.
Read more about this topic: Continuing Patent Application
Famous quotes containing the words early and/or history:
“Mormon colonization south of this point in early times was characterized as “going over the Rim,” and in colloquial usage the same phrase came to connote violent death.”
—State of Utah, U.S. public relief program (1935-1943)
“The history of the world is the record of the weakness, frailty and death of public opinion.”
—Samuel Butler (1835–1902)