What prominent structure in Nebraska was once the tallest building in the U.S.?

The correct answer is the First National Bank Tower. This building, located in Omaha, held the title of the tallest building in the United States for a brief period during the 1960s. It was completed in 1963 and stands at 634 feet tall, boasting a significant presence in the Omaha skyline.

The First National Bank Tower is recognized for its distinctive architecture and historical importance, symbolizing the growth and development of the region during that time. Its status as a skyscraper not only marks an achievement in Nebraska's architectural landscape but also reflects the economic progress of the state.

The other structures mentioned, such as the Nebraska State Capitol, while notable for their unique designs and historical significance, did not reach the height or prominence of the First National Bank Tower in terms of being the tallest building in the U.S. during their respective eras. The Nebraska State Capitol is known for its beautiful art deco architecture but does not have the same height record. Similarly, the Omaha Building and Lincoln's Woolworth Building, while part of Nebraska’s historical architecture, do not hold a comparable title to that of the First National Bank Tower.