Sorry to rain on the parade, but that information is typical of the sort of shambles you would get if you believed trees on Ancestry.
Scotland's People has a record of the marriage of Daniel McAlpin to Marion Graham in Glasgow in 1778, and baptisms of nine children, all in Glasgow:
all in Glasgow.
Therefore Marion Graham's husband was still fathering children in Glasgow AFTER the marriage of your Daniel to Catherine Isabella Munn in 1792 on the other side of the Atlantic. Therefore they are not the same Daniel McAlpin.