The timing shift is large and symmetrical
Census estimated a 2025 median of 30.8 for men and 28.4 for women. Both are 7.3 years higher than the corresponding 1975 estimates.
The long historical table documents the trend using Current Population Survey and earlier census sources. It is stronger evidence for timing than an anecdote about one generation.
One trend can have many contributors
Education, labor markets, housing costs, cohabitation, contraception, norms, and personal goals can all be discussed as possible contributors in research. The median-age table itself does not estimate each cause.
A responsible answer separates the measured fact—later first marriage—from causal interpretations that require dedicated studies.
Later marriage does not mean less partnership
Marriage is one relationship status. Cohabitation and committed relationships outside a shared household can change even when first-marriage age rises.
The dating pool likewise includes people with different intentions. A national first-marriage trend cannot tell an individual when to marry or predict the success of a relationship.