13 covers including Andover "Andr. Ms." datestamp in black (1817), red (1818/31), and brown (1821), 1837 "Andr. Ms." datestamp with fleuron, 1842 orange datestamp, 1845 and 1847 datestamps with numeral "5" and "10"; North Andover 1826 and 1829 manuscript postmarks, 1836 "No. Andover" datestamp, 1838 "North Andover" datestamp; and ca. 1849 Ballardvale blue datestamp (earliest recorded), generally fine to very fine