The Gunners are in Pennsylvania's largest city preparing for the final game of their pre-season tour to the USA.
Another big crowd is expected on Wednesday after 62,486 fans watched Arsenal's victory over United.
Arsenal's American fans are very passionate about their club and that was highlighted further by a video that has recently gone viral.
The video was taken at Philadelphia Union's Subaru Park stadium, where Arsenal have been training.
It showed one Gunners fan looking overwhelmed after meeting right back White.
After passing White a shirt through a set of metal bars, the fan was pictured sobbing with joy as his hero signed it with a pen.
'I love you Ben,' he spluttered, before White politely replied: 'Thanks for coming.'
The fan then said: 'Thank you so much, thank you so much,' as White handed him back the jersey.
However, White was seemingly not even this fan's favourite player because the shirt that he signed was printed with Bukayo Saka's name and number.
The video was shared via X (formerly Twitter) by multiple accounts and it generated thousands of comments.
Many of them focussed on the fact that the fan's shirt - which he attached to a coathanger before leaving the stadium - did not have White's name on it.
Another Gunners fan wrote: 'Saka shirt but crying for White', followed by two crying emojis.
White, 28, was one of Arsenal's best players last season.
The former Brighton defender featured in 37 of Arsenal's 38 Premier League games.
Meanwhile, Saka ended the 2023-24 campaign as Arsenal's leading scorer with 16 goals in 35 league appearances.
Arsenal will begin the new season on August 17 with a home game against Wolves.