Complex sentence: Richard Henry Dana III (3 January 1851-16 December 1931) was an American lawyer and civil service reformer, the son of Richard Henry Dana, Jr.; he married Edith Longfellow, the daughter of poet Henry Wadsworth Longfellow.
Split into simpler sentences: Richard Henry Dana III (3 January 1851-16 December 1931) was an American lawyer and civil service reformer. Dana was the son of Richard Henry Dana, Jr.; he married Edith Longfellow, the daughter of poet Henry Wadsworth Longfellow.