law firm of Holland & Knight was founded in Bartow in 1929. What eventually become the large Burdines and Sons department store chain was founded in Bartow in 1896 as Payne and Burdines. A couple years after opening his store, William M. Burdines opened a store in Miami and relocated his operations there. Phosphate mining has been a major player in Bartow's economy since the discovery of phosphate rock in 1881. Polk County is part of the Bone Valley which is the richest source of phosphate rock in the world; 75% of the United States's supply and 25% of the world's supply come from the Bone Valley. The largest employer in the phosphate industry is Mosaic which employs over 3,000 people in the area. In terms of area, Polk County has dedicated to agriculture. According to the US Census of Agriculture, Polk County is the top citrus production county in Florida. Polk County is also ranked second in the state in production of honey and fourth in number of heads of cattle. Since 1997 the new bumper crop in the area is blueberry. From 2000−07 the area has more than doubled its production of blueberries and accounts for more than 35% of the state's production of the fruit. While spring is usually a "dead" time for every other blueberry growing area in North and South America, Polk County blueberries peak from March to May. Although there are no major tourist attractions in the immediate Bartow area, the city is located less than from both the Walt Disney World Resort and Busch Gardens Tampa Bay. The city is also less than from Legoland Florida in Winter Haven and Bok Tower Gardens in Lake Wales. As a city with many historical sites dating back over 100 years, Bartow is also a point of interest for those interested in historical sites and monuments. Culture Annual festivals and other events There are several annual events in the Bartow area which have a long tradition. Many of these are large events which draw people from other communities to the city such as the Cricket Club Halloween Parade and Carnival held each year since 1942 or the annual Fourth of July Celebration held at Mosaic Park. The Bloomin' Arts Festival is an art show held in early March by the Bartow Art Guild. Every February brings the Annual L.B. Brown Festival at the L.B. Brown House