Complex sentence: In the late 1970s, WBBM-TV's newscasts surged past WMAQ-TV for first place; its news department during this time had become one of the most respected local news operations in the country, and was considered a bastion of serious journalism.
Split into simpler sentences: In the late 1970s, WBBM-TV's newscasts surged past WMAQ-TV for first place. It became one of the most respected local news operations in the country and was considered a bastion of serious journalism.