The maximal correlation problem (MCP) aiming at optimizing correlation between sets of variables plays a very important role in many areas of statistical applications. Currently, algorithms for the general MCP stop at solutions of the multivariate eigenvalue problem (MEP) for a related matrix A. The MEP is a necessary condition for the global solutions of the MCP. Up to date, there is no algorithm that can guarantee convergence to a global maximizer of the MCP, which would have significant impact in applications. Towards the global solutions of the MCP, we have obtained four results in the present paper. First, the sufficient and necessary condition for global optimality of the MCP when A is a positive matrix is extended to include A being a nonnegative irreducible matrix. Secondly, the uniqueness of the multivariate eigenvalues in the global maxima of the MCP is proved either when there are only two sets of variables involved, or when A is nonnegative irreducible, regardless of the n...