How do you automatically number cells in a grid with row numbers and column numbers (or letters)

Question

I have a fishnet grid consisting of 330 rows and 330 columns. Each cell is 500 feet x 500 feet. The centroids of each cell is 500 feet from its adjacent centroid throughout the grid. Also, the centroid points have been extracted for each polygon (i.e. cell) as well as adding an X and Y field, and calculating the geometry to get those values.

Now comes the fun part. I would like to find a way to automatically number each row (top to bottom) and each column (left to right). In other words, first row would all have the number "1" in each cell, the second row would all have the number "2" in each row, etc. without having to resort to selecting each row and Field Calculate a "1", "2", "3", etc. for 330 rows or "A", "B", "C", etc. for 330 columns.

Answer 1

You could try looking at the Grid Index Features of the Map Series Toolset. Hopefully your grid does not have too many attributes already applied.

https://pro.arcgis.com/en/pro-app/latest/tool-reference/cartography/grid-index-features.htm