While many United Methodist congregations operate in the evangelical tradition, others reflect the mainline Protestant traditions. Although United Methodist practices and interpretation of beliefs have evolved over time, these practices and beliefs can be traced to the writings of the church's founders, especially John Wesley and Charles Wesley (Anglicans), but also Philip William Otterbein and Martin Boehm (United Brethren), and Jacob Albright (Evangelical Association). With the formation of The United Methodist Church in 1968, theologian Albert C. Outler led the team which systematized denominational doctrine. Outler's work proved pivotal in the work of union, and he is largely considered the first United Methodist theologian.