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Spectroscopy of 333 NGC 6819 stars and Gaia astrometry are used to map Lievolution from the giant branch tip to 0.5 mag below the Li dip. Isochronecomparison with [Fe/H] = -0.04, based upon neural network spectroscopicanalysis, produces an age of 2.25 (2.4) Gyr for E(B-V) = 0.16 (0.14) and (m-M)= 12.40 (12.29). Despite originating outside the Li dip, only 10% of singlesubgiants/giants have measurable Li. Above the Li dip, the limiting A(Li) forsingle stars is 3.2 +/- 0.1 but the lower range is comparable to that foundwithin the dip. The F-dwarf Li dip profile agrees with the Hyades/Praesepe,evolved forward. The Li level among stars populating the plateau fainter thanthe Li dip is A(Li) = 2.83 +/- 0.16; the dispersion is larger than expectedfrom spectroscopic error alone. Comparison of Li and V_ROT distributions amongturnoff stars in NGC 7789, NGC 2506, NGC 3680, and NGC 6819 indicates thatrotational spindown from the main sequence is critical in defining theboundaries of the Li dip. For higher mass dwarfs, spindown is likewisecorrelated with Li depletion, creating a second dip, but at higher mass and ona longer time scale. The Li distribution among evolved stars of NGC 6819 ismore representative of the older M67, where subgiant and giant stars emergefrom within the Li dip, than the younger NGC 7789, where a broad range in V_ROTamong the turnoff stars likely produces a range in mass among the giants.

Li Evolution and the Open Cluster NGC 6819: A Correlation Between Li Depletion and Spindown in Dwarfs More Massive Than the F-Dwarf Li-Dip