Laredo is the county seat of Webb County, Texas, United States, on the north bank of the Rio Grande (Río Bravo) river, across from Nuevo Laredo, Tamaulipas, Mexico. According to the 2006 census estimate, the city population was 231,470. Laredo is part of the Laredo-Nuevo Laredo Metropolitan Area with a total population of 589,309. Laredo's economy is primarily based on international trade with Mexico whereas it has the distinction of being the largest inland port in the United States. Most major transportation companies have a facility in Laredo. Laredo's location along the southern end of IH-35 and in proximity with maquiladoras (manufacturers) in North Mexico promotes its vital role in trade between the United States and Mexico. Laredo has the distinction of having seven flags flown over the city. Having been founded in 1755, Laredo grew from a villa to the Capital of the brief Republic of the Rio Grande to the largest inland port on the United States-Mexican Border. Today, it has four international bridges and one railway bridge. Laredo's weather is semi-arid during the summer and mild during the winter. Laredo International Airport is within the Laredo city limits, while the Quetzalcoatl International Airport is nearby in Nuevo Laredo in Mexico. The city has four professional sports teams: the Bucks, Broncos, Heat, and Lobos. Texas A&M International University and Laredo Community College call Laredo home. The biggest festival, Washington's Birthday Celebration is during February all month long, attracting hundreds of thousands of tourists.