Start by peeling the potatoes and cutting them into cubes. Rinse the cubed potatoes under cold water to remove any excess starch.
In a large pot, add the cubed potatoes and cover them with cold water. Add a pinch of salt to the water. Bring the water to a boil over medium-high heat.
Reduce the heat to medium-low and let the potatoes simmer for about 10-15 minutes or until they are tender. To check if they are cooked, insert a fork into a potato cube. If it easily slides in and out, they are done.
While the potatoes are cooking, prepare the dressing. In a separate bowl, combine the mayonnaise, Dijon mustard, white vinegar, chopped parsley, sugar, salt, and pepper. Whisk together until well combined.
Once the potatoes are cooked, drain them in a colander and rinse with cold water to stop the cooking process. Allow them to cool completely.
In a large mixing bowl, add the cooled potatoes, diced celery, and diced red onion.
Pour the prepared dressing over the potatoes and vegetables. Gently toss everything together until the potatoes are well coated with the dressing.
Taste and adjust the seasoning by adding more salt and pepper if needed.
For an extra touch, garnish the potato salad with sliced hard-boiled eggs. You can place the egg slices on top of the salad or arrange them around the edges.
Cover the bowl with plastic wrap or a lid and refrigerate for at least an hour to allow the flavors to meld together and the salad to chill.
Once chilled, give the potato salad a final toss before serving.
Serve the classic American Potato Salad as a side dish at your next gathering or alongside your favorite grilled meats. It's also delicious on its own as a light and refreshing meal option.