Magnetic hysteresis, flux pinning, and flux creep in melt-powder-melt-growth processed ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7}$ (Y 1:2:3) containing nominal 0, 25, and 40 mol % concentration of ${\mathrm{Y}}_{2}$${\mathrm{BaCuO}}_{5}$ (Y 2:1:1) inclusions were investigated. The strong pinning due to 2:1:1-phase precipitates in these samples allows for characterization of the hysteretic response as a function of pinning-site concentration over a large portion of magnetic-field--temperature space. We have found the following: (i) The curves of effective pinning energy ${\mathit{U}}_{\mathrm{eff}}$ versus current density J reveal a diverging behavior of ${\mathit{U}}_{\mathrm{eff}}$(J) in the low-J regime. This supports the existence of a vortex-glass state, and is a signature of a vanishing resistance as the current density approaches zero. (ii) Both the ${\mathit{U}}_{\mathrm{eff}}$ and the J values obtained from magnetic hysteresis loops were observed to increase with Y 2:1:1 concentration. The appearance of the butterfly-shaped (or ``fishtail'') hysteresis loops indicates a ${\mathit{J}}_{\mathit{c}}$ that is an increasing function of H (or B). Moreover, it has been demonstrated that the additional pinning leads to an increase in ${\mathit{U}}_{\mathrm{eff}}$ in an H-T region in which the butterfly is developed.The derived effective pinning energy is fit, from the instantaneous experimental relaxation data, to the relation, ${\mathit{U}}_{\mathrm{eff}}$(J,T,H)=${\mathit{U}}_{\mathit{i}}$[G(T)/${\mathit{H}}^{\mathit{n}}$](${\mathit{J}}_{\mathit{i}}$/J${)}^{\mathrm{\ensuremath{\mu}}}$, where ${\mathit{U}}_{\mathit{i}}$ is the scale of the activation energy, G(T) =[1-(T/${\mathit{T}}_{\mathit{x}}$${)}^{2}$${]}^{\mathit{m}}$, and ${\mathit{T}}_{\mathit{x}}$ is close in value to ${\mathit{T}}_{\mathrm{irr}}$(H) (the irreversibility line of the material). This description breaks down in the vicinity of the ``butterfly'' peak. We observed two power-law regimes of J dependence of ${\mathit{U}}_{\mathrm{eff}}$ which have \ensuremath{\mu} values that agree qualitatively with the theoretical predictions (=7/9 and 3/2) for a three-dimensional flux-line lattice.