We report a robust one-dimensional (1D) nanoparticle-assembly strategy that uses the self-assembly of nanoparticles with ligand and thermal controls, polyethylene glycol (PEG) with thiol and carboxyl groups, and nanoparticle oligomer and polymer codewetting process to form ultralong and continuous 1D nanochains. The 1D nanochains were assembled with closely packed 1D nanoparticle oligomer building blocks, elongated and buttressed by dynamic 1D PEG templates formed on a hydrophobic surface via anisotropic spinodal dewetting. Using this strategy, nanoparticle-packed 1D nanochains (similar to 1 nm interparticle spacing) were fabricated with similar to 60 nm-width and a few to >10 mu m-length (nearly 20 mu m in some cases) from 20 nm gold nanoparticles. Our findings offer insights and open revenues for particle assembly processes and, as given by universality in colloid aggregation, should be readily applicable to various nanoparticles.