Complex sentence: Whalen was involved in improving the City's image both domestically and worldwide; the City was designated an "All-American City" under his leadership, attained the highest possible bond rating from Moody's and hosted many successful downtown cultural events.
Split into simpler sentences: Whalen was involved in improving the City's image both domestically and worldwide. The City was designated an "All-American City" under his leadership, attained the highest possible bond rating from Moody's and hosted many successful downtown cultural events.