Complex sentence: Barnes served as state Speaker of the House in Texas from 1965-1969, U.S. representative to the NATO Conference in 1967, and United Nations Representative to Geneva, Switzerland, in 1968.
Split into simpler sentences: Barnes served as state Speaker of the House in Texas from 1965-1969. He was also U.S. representative to the NATO Conference in 1967, and United Nations Representative to Geneva, Switzerland, in 1968.