I found it...

LPC, stands for "Likely Public Charge." The LPC exclusion was introduced to US immigration law in 1891 and was the most common cause of detention and grounds for exclusion/deportation. Immigrants were most likely considered a likely public charge if they had little money AND no family, friends, or prospects, OR if they were disabled in some way that would prevent them from earning their own living. The majority of LPC exclusions were overcome during the Special Inquiry process, usually when friends, family, or some Immigrant Aid organization came and vouched for the person or posted a bond for them.