Columnar organization is the hallmark of mature visual cortex in primates and carnivores, and is often assumed to be unique to those areas. Such an organization is already evident in the developing visual cortex (V1) well before eye-opening, where correlated modular spontaneous activity predicts future sensory-evoked representations. The multiple computational models proposed to account for this modular activity suggest several biologically plausible regimes which can produce modular activity and long-range correlations. Notably, these potential mechanisms are highly unlikely to be specific in early development to primary visual cortex, raising the question of whether modular and correlated networks exist beyond V1. Here we demonstrate that highly organized, modular, and well correlated network structure is a universal feature of the early developing cortex in a species with a columnar V1. Using a combination of wide-field and multi-photon calcium imaging of spontaneous activity in the ferret prior to eye-opening, we find that both primary sensory cortices (V1, auditory [A1], and somatosensory [S1]) as well as association cortices (prefrontal [PFC] and posterior parietal [PPC]), all exhibit similar modular patterns of low dimensional neural activity with robust correlations across millimeters. Moreover, we find that while both the degree of modularity and the strength of long-range correlations declines with age, spontaneous activity remains predominantly modular at the cellular level across areas. Notably, activity becomes increasingly sparse and higher dimensional, suggesting an improved representational capacity with increasing maturity. Furthermore, similar to published reports in V1, sensory evoked activity in A1 exhibits strongly modular responses with significant statistical similarity to spontaneous activity, suggesting that early spontaneous networks seed developing cortical representations in sensory areas and raising the possibility of a similar relationship in higher association areas such as PFC. Together, our findings suggest that the diverse representations found across neocortex may arise from a common developmental origin.