My ancestors, Italian, and Irish, settled in Philadelphia between the 1880s and 1930s. Unfortunately, none are alive for me to ask this question to. At a time when New York was growing at such a rapid speed to become America's dominant city, why did so many choose to settle in Philadelphia, a city geographically close to New York, but smaller?
Between 1873 and roughly World War I, Philadelphia was actually a major port of call for immigrants arriving from Europe. The American Line was especially important, operating a Liverpool=>Queenstown, Ireland=>Philadelphia route. The Red Star Line steamed from Antwerp (Belgium). Around the turn of the 20th century, the Hamburg-American Line--which also operated a New York/New Jersey route at an earlier date--added a Hamburg (via rail)-Boston-Philadelphia run.
Because the Philadelphia journey took longer than New York and could be psychologically treacherous (you were in sight of land for the last leg up the Delaware River!), in some cases companies discounted the tickets to make it more attractive.
Depending on when they arrived, stops for processing at a place like Reedy Island plus the Washington Avenue railway station (really) would have served a similar purpose to Ellis Island in New York.
In most cases, Philadelphia served as a transit stop for migration further west--hence the use of the railway station for processing. However, the city was no slouch. A massive buildup of industry created accessible job opportunities, and housing was cheap.
Do you know if your ancestors came to the US via Philly? Because that would basically explain it.