Spicer is no doubt an ancestral name.I found 16 Spicers on DAR's Patriot Index.
On Find-A-Grave website (free) I found 2 listings for Jacob Spicer Horner b. 1773 NJ; d. 1852 IN buried at Horners Chapel Cemetery, Fredericksburg, Washington Co., IN. To view listings go to site and click on Search 50 million graves then type in Jacob Spicer Horner.
Hope this helps and not confusing you any further!