  We study the evolution from few- to many-body physics of fermionic systems in
one spatial dimension with attractive pairwise interactions. We determine the
detailed form of the momentum distribution, the structure of the one-body
density matrix, and the pairing properties encoded in the two-body density
matrix. From the low- and high-momentum scaling behavior of the single-particle
momentum distribution we estimate the speed of sound and Tan's contact,
respectively. Both quantities are found to be in agreement with previous
calculations. Based on our calculations of the one-body density matrices, we
also present results for the particle-partition entanglement entropy, for which
we find a logarithmic dependence on the total particle number.
