Species time-history measurements provide important kinetics targets for the development and validation of detailed reaction models. Here, a multi-wavelength, multi-species laser absorption strategy is demonstrated that provides high-bandwidth species time-histories during 1-butene pyrolysis behind reflected shock waves. Measured shock tube absorbance traces at nine wavelengths were used to resolve nine species mole fractions in the pyrolysis of 5% 1-butene in argon at 1300 K, 1.8 atm. In addition to existing sensors for 1-butene, methane, ethylene, 1,3-butadiene, propene, allene, benzene, and cyclopentadiene, a new laser absorption sensor for ethane at 3.3519 mu m was developed by measuring cross-sections of ethane and of expected major interferers. Additional measurements to complete a square absorption cross-section matrix were also performed that enabled the simultaneous solution of species mole fractions from absorbance time-histories under appropriate physical system constraints. Measured time-histories of the nine product species were also compared with existing flow-reactor-based kinetic mechanisms. The demonstrated method has further application potential in the speciation of larger, more complex fuels.