We present a local-to-global cosmological framework in which cosmic acceleration emerges from structure formation in an inhomogeneous Einstein–de Sitter (iEdS) universe, without dark energy. The model exhibits a quasilinear coasting evolution toward an effective Milne state driven by growing inhomogeneities. We test the iEdS model with 𝐻0 =72.5  km s−1 Mpc−1 and Ωm,0=0.272 using cosmic microwave background, baryon acoustic oscillation, and type Ia supernova data. The iEdS model fits the data comparably to Λ⁢CDM and resolves the 𝐻0 tension, while yielding a cosmic age 𝑡0 ≃13.67  Gyr consistent with globular-cluster estimates.