Space-division multiplexing (SDM) has been intensively proposed in recent years to overcome the capacity limitations of the current single-mode fiber infrastructure and to increase the efficiency of optical transmission systems. Few-mode fibers offer the potential of transmitting several signals at the same wavelength over different modes of a fiber with one single core. In this paper, we demonstrate the potential of using few-mode fiber-based SDM systems for long-haul transmission. We analyze system limitations such as mode-dependent loss and Kerr-effect-based nonlinear signal distortions for different modulation formats and distances up to 3500 km. We find that mode-dependent loss poses the major limitation in the analyzed transmission system, masking most intermodal nonlinear interactions.