About Illinois 15th Congressional District: 

The 15th district covers a very large area of land in East Central Illinois. It includes the counties of Clark, Clay, Clinton, Coles, Crawford, Cumberland, Douglas, Edgar, Edwards, Effingham, Fayette, Gallatin, Hamilton, Hardin, Jasper, Johnson, Lawrence, Marion, Massac, Moultrie, Pope, Richland, Saline, Shelby, Vermilion, Wabash, Washington, Wayne, and White counties and portions of Bond, Champaign, Ford, and Madison counties. This is a very, very Republican district. Since the last congressional redistricting in 2010, a Republican has held this seat. The seat is currently held by John Shimkus, who is not seeking reelection. From Ballotpedia:

The 2017 Cook Partisan Voter Index for this district was R+21, meaning that in the previous two presidential elections, this district's results were 21 percentage points more Republican than the national average. This made Illinois' 15th Congressional District the 29th most Republican nationally.

About Mary Miller:

Mary Miller, the Republican candidate, is a graduate of Eastern Illinois University with degrees in Business Management and Elementary Education. She runs a family farm with her husband in Oakland, IL. From her website:

Mary Miller is a wife, a mother, a grandmother, a local farmer, and a business manager. She is running for Congress to help local families and ensure each Illinoisan can pursue their version of the American dream. Mary will be a voice for the families and businesses ignored by D.C. insiders and fight for our Midwestern values of faith, family, and freedom while bringing much-needed reform to Washington.

About Erika Weaver:

Erika Weaver, the Democratic candidate has an Associate’s degree in Business Administration from Lake Land College, earn a Bachelor's degree in Kinesiology, Sports, & Recreation and a Master's degree in College Student Affairs, both from Eastern Illinois University. She then went on to Loyola University Chicago School of Law, and now works in the Coles County Public Defender's Office. From her website:

Erika shares many of the lived experiences of people in our district. She knows firsthand the struggle to balance limited finances, provide for a family, and work hard to move into a better position. Her decision to run for office was not based on her struggles, but the resiliency and perseverance to overcome them. She entered this race because she wants every family to have the opportunity to create and define their American Dream, but without the hardships she endured. Her campaign reflects and embodies her life, her work, and her heart for service.

Top image of (l) Mary Miller and (r) Erika Weaver from each candidate's respective Facebook page.