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We present Spitzer IRS R ~ 600 spectra (10 - 38 μm) of 38 positions in the Galactic Center (GC), all at the same Galactic longitude of and including the Arches Cluster. Our positions include the Arched Filaments, regions near the Quintuplet Cluster, the ''Bubble'' lying along the same line-of-sight as the molecular cloud MO.13-0.13, and the diffuse interstellar gas along the line of sight at higher Galactic latitudes. From measurements of the [O IV], [Ne II], [Ne III], [Si II], [S III], [Fe II], [Fe III], and H2 S(0), S(1), and S(2) lines we determine the gas excitation and ionic abundance ratios. The main source of excitation is photoionization, with the Arches Cluster ionizing the Arched Filaments and the Quintuplet Cluster ionizing the gas nearby and at lower Galactic latitudes including the far side of the Bubble. In addition, strong shocks ionize gas to O+3 and destroy dust grains, releasing iron into the interstellar medium (ISM); the shock effects are particularly noticeable in the center of the Bubble but the highly ionized gas is present in all positions. The H2 lines are formed both in photodissociation regions in the GC and along the line of sight to the GC.