City directories were a new concept in the middle of the 18th century. Throughout much of history no one needed one, as they already knew-- or soon did by word of mouth-- everyone they needed to, and where they lived, and no one made such a unique product that anyone not living nearby might need to know how to go and get one. The tremendous expansion in the manufacture of goods that occurred beginning in the 17th century, with improvements in communication and the population increase facilitated by colonization, combined to make city directories the right idea for the era. Directories were of course difficult without street numbering, which had occurred in London by the 1770s.
In 1785, in the foremost city in the two-year-old United States, two Philadelphia men raced to put out the first-ever city directory in America. Each took a different approach. Francis White gave almost everyone's profession, but listed only the street and block they lived on, dealt more or less only with the city proper (back then, only between South Street and Vine) and at that, failed to list everyone. Captain John MacPherson was more methodical but less practical. He listed everyone, even those who refused to give their name or who gave impudent answers, and gave the professions only of subscribers. He was also the first to assign numbers to Philadelphia houses, but in doing so went straight up one side of a street and down the other, so that 1 Arch Street might be across the street from 300 Arch Street. He also assigned numbers to outbuildings such as stables and other utilitarian structures, and to where he thought houses might some day be built. Since everyone used the street-and-block system followed by White and many Philadelphians could not read anyway, it is not surprising that many more copies of White's more useful directory are known; it probably sold many more copies than MacPherson's.