  We investigate the spin contribution to light baryon ground states in three
inequivalent large-$N$ limits: 't Hooft, QCD antisymmetric and QCD symmetric.
Our framework is a constituent quark model with a relativistic Hamiltonian
containing a stringlike confinement and a one-gluon exchange term. Two
spin-dependent potentials are considered and treated as perturbations: the
color magnetic interaction stemming from the one-gluon exchange process and the
chiral boson exchange interaction. We analytically prove that the spin
contributions scale like $S(S+1)/n_q$, where $S$ is the total spin and $n_q$ is
the number of quark, in agreement with diagrammatic methods. Both potentials
yield also $S$-independent contributions which scale at most as O$(n_q)$.
