Do you know the saying, “Never say never” and why it is so important? You never know when you can win again or for the first time. What is important is that you have to keep trying. For the Philadelphia Eagles, it took them 56 seasons to win for the first time, and before this Super Bowl, there were a lot of doubts about them. They had 2 other opportunities but lost them both, the first in 1981 against the Raiders and the second in 2005 against the Patriots, so they had to keep trying.
Whether the Philadelphia Eagles would ever win a Super Bowl was a question that was answered on February 4th, 2018, when they beat the New England Patriots. The final result was 41-33, and on this link you can watch the game highlights.
It was really intense throughout the game. One of the most crucial moments of the game, which you can watch here, was the Tom Brady turnover that sealed the victory for the Eagles.
They went 56 seasons without winning a Super Bowl, one of the longest droughts in sports only behind the Detroit Lions with 60 seasons, which you can check out in wikipedia droughts in sports. If you want to know a bit of their history, it is answered in Quora. This article was written in 2015, but it explains very well why it has taken so long for the Eagles to win.