Progressive Era
- Abercrombie, James Smither
- Adams, John Maurice
- Addicks, TX
- African Americans
- Agriculture
- Aguirre, Lauro
- Alarcon, Francisca [Doña Paca]
- Allen Ranch
- Allen, Henry Tureman
- Allen, Samuel Ezekiel
- Almeda, TX
- Ames, Jessie Harriet Daniel
- Ancient Order of Pilgrims
- Anderson, Clayton and Company
- Anderson, Katherine Finnigan
- Anderson, Monroe Dunaway
- Anderson, Ralph Alexander, Sr.
- Andrews, Frank
- Andrews, Jesse
- Anti-Saloon League of Texas
- Antoine, George Washington
- Antonio Gómez Lynching
- Armijo, Marcos B.
- Aves, Charles Marion
- Aves, Henry Damerel
- Axson, Stockton
- Azuela, Mariano
- Bailey, Joseph Weldon
- Baker Botts
- Baker, Alice Graham
- Baker, Jess Alexander
- Baker, Robert Holmes
- Baldwin, William Wright
- Ball, Thomas Henry
- Baptist Church
- Barker, TX
- Barkley, David Bennes
- Barry, Bryan Thomas
- Baugh, William Lofton
- Bayland Orphans' Home For Boys
- Baylor College of Medicine
- Bellaire, TX
- Benbrook Field
- Berachah Home
- Bertner, Ernst William
- Beville, Alexander Archer
- Bickler, Martha Lungkwitz
- Binnion, Emma Shanklin
- Bloor, Alfred Wainwright
- Blues