Summary: We consider both closed and open integrable antiferromagnetic chains constructed with the \(\text{SU}(N)\)-invariant \(R\)-matrix. For the closed chain, we extend the analyses of Sutherland and Kulish-Reshetikhin by considering also complex “string” solutions of the Bethe ansatz equations. Such solutions are essential to describe general multiparticle excited states. We also explicitly determine the \(\text{SU}(N)\) quantum numbers of the states. In particular, the model has particle-like excitations in the fundamental representations \([k]\) of \(\text{SU}(N)\), with \(k= 1,\cdots,N-1\). We directly compute the complete two-particle S-matrices for the cases \([1]\otimes[1]\) and \([1]\otimes [N-1]\). For the open chain with diagonal boundary fields, we show that the transfer matrix has the symmetry \(\text{SU}(l)\times\text{SU}(N-l)\times\text{U}(1)\), as well as a new “duality” symmetry which maps \(l\leftrightarrow N-l\). With the help of these symmetries, we compute by means of the Bethe ansatz for particles of types \([1]\) and \([N-1]\) the corresponding boundary \(S\)-matrices.