Use of school uniforms in the U.S. started in the early 1900's for parochial and private schools, but it wasn't until the 1980s that public schools began to use uniforms. Schools in Maryland and Washington D.C. were the first to implement uniform policies, although they were voluntary, according to ProCon.org. School officials at this time noticed changes in the students' attitudes as well as a decline of disciplinary issues after the uniform policy was introduced. This led a few other schools to start using uniforms as well.