Initiation of the modern era of surface science is generally acknowledged to have occurred in the 1960's, a period marked by the recognition and development of measurement and theoretical techniques for studying surface properties and processes on the (single!) atomic level. Resonance tunneling of field emitted electrons through adsorbates on metal surfaces reported in a 1969 NBS paper was the first-ever work in which the electronic energy level spectra of adsorbed atoms was observed and theoretically interpreted (as "skewed" Fano profiles).@footnote 1,2@ Variants and extensions of the theory have formed the basis for subsequent NBS/NIST studies of resonant tunneling/scattering phenomena involved in desorption,@footnote 3@ basic STM operation,@footnote 4@ quantum wells,@footnote 5@ scanning tunneling spectroscopy of Kondo systems,@footnote 6@ and molecular electronics.@footnote 7@ A useful synergism amongst these studies illustrates the positive consequences of a long-term commitment to the search for varied realizations of a common fundamental process (here resonance tunneling). Fortunately this research strategy has been possible at NBS/NIST throughout much of its first 100 years.@footnote 8@ @FootnoteText@ @footnote 1@ E.W.Plummer, J.W.Gadzuk, and R.D.Young, Solid State Comm.7(1969)487. @footnote 2@ J.W.Gadzuk and E.W.Plummer, Rev.Mod.Phys. 45(1973)487. @footnote 3@ J.W.Gadzuk, Phys.Rev.B44(1991)13466. @footnote 4@ J.W.Gadzuk, Phys.Rev.B47(1993)12832. @footnote 5@ A.Bringer, J.Harris, and J.W.Gadzuk, J.Phys.:Condens.Mat.5(1993)5141. @footnote 6@ M.Plihal and J.W.Gadzuk, Phys.Rev.B63(2001)085404. @footnote 7@ A.Aviram and M.Ratner, Chem.Phys.Letters 29(1974)277. @footnote 8@ A Century of Excellence in Measurements, Standards, and Technology, NIST Special Publication 958, ed. by D.R.Lide(2001).