Recent work indicates that the nearby Galactic halo is dominated by the debris from a major accretion event. We confirm that result from an analysis of APOGEE-DR14 element abundances and Gaia -DR2 kinematics of halo stars. We show that ∼2/3 of nearby halo stars have high orbital eccentricities (e ≳ 0.8), and abundance patterns typical of massive Milky Way dwarf galaxy satellites today, characterized by relatively low [Fe/H], [Mg/Fe], [Al/Fe], and [Ni/Fe]. The trend followed by high- e stars in the [Mg/Fe]–[Fe/H] plane shows a change of slope at [Fe/H] ∼ −1.3, which is also typical of stellar populations from relatively massive dwarf galaxies. Low- e stars exhibit no such change of slope within the observed [Fe/H] range and show slightly higher abundances of Mg, Al, and Ni. Unlike their low- e counterparts, high- e stars show slightly retrograde motion, make higher vertical excursions, and reach larger apocentre radii. By comparing the position in [Mg/Fe]–[Fe/H] space of high- e stars with those of accreted galaxies from the EAGLE suite of cosmological simulations, we constrain the mass of the accreted satellite to be in the range 108.5 ≲ M * ≲ 109 M⊙. We show that the median orbital eccentricities of debris are largely unchanged since merger time, implying that this accretion event likely happened at z ≲ 1.5. The exact nature of the low- e population is unclear, but we hypothesize that it is a combination of in situ star formation, high-| z | disc stars, lower mass accretion events, and contamination by the low- e tail of the high- e population. Finally, our results imply that the accretion history of the Milky Way was quite unusual. [ABSTRACT FROM AUTHOR]