As early as 20 January 1899, US President William McKinley established the Philippine commission and instructed it to report on, among other matters, the currency situation in the Philippines, the newly independent republic who God supposedly told him to "Christianize and civilize". The Commission said that if there were monetary changes to be made, a dollar of the same weight as the Mexican silver one could circulate, but a new symbol distinct from the US dollar sign had to be configured to avoid confusion.
Someone suggested that the capital letter P be used to denote Philippine money because the word Philippines starts with a P, so does the word peso, and the Spanish word for silver which is plata. Moreover, the letter P is found on all typewriters. The naming game must have attracted the attention of American Judge Charles E. Magoon, acting chief of the Bureau of Insular Affairs, who immedidately sent a telegram to Governor William H. Taft in Manila. He supported the idea but said the letter P should be in capitalized Roman font with two parallel lines "passing through and extending slightly beyond loop at right angle to shaft or stem..."
That design was promulgated by the US colonial government through Executive Order No. 66, which stipulated that the Roman character P with the two lines be used",,,by all officials as the designation of the new Philippine pesos to differentiate it from the $ mark for United States currency and Pts. of Spain..." That was how the peso got its P. #