I need to measure the distance (with the ruler) of points from two different layers. One layer is NAD83 and the other is NAD27. When importing the NAD27 csv file, I specified it was NAD27. Then I used: Toolbox-> Data Management -> Projections and Transformations -> Project and I projected from the input coordinate system of NAD27 to the output coordinate system of NAD83.
The issue is that I have a ton of CSV files, each with data from different projections (there is a column that specifies projection). I use Microsoft Access to connect a lot of tables and then extract the data I need, save in a table, and import to ArcGIS. The problem is that after I just transformed my NAD27 to NAD83, the lat/long in the actual table is still the same, so if I join the tables and extract data later on, I will have to do the transformations all over again.