We present a large-scale harmonized dMRI study where we have performed successful white matter(WM) tractography parcellation across ~10k subjects from the ABCD study. We first assess the effects of data harmonization on WM parcellation, followed by an evaluation of WM parcellation using the entire harmonized dataset. We show that after harmonization, more anatomical tracts are identified and their FA values are closer to the harmonization reference data. We also demonstrate highly successful WM parcellation, where overall 99.9% of tracts(73 per subject) are identified. The parcellated WM tracts, as well as their diffusion measures, will be made available to the public.