From June 4 to 11, 1969, the Bau-Steine-Erden industrial union held its eighth regular trade union conference in the Rhein-Main-Hallen. At the same time, the union celebrated its 100th anniversary.

To mark this anniversary, the city council invited the union's executive board to a reception in the ballroom of the town hall on the evening of June 9. Mayor Schmitt paid tribute to the work of the trade unionists and congratulated them on the association's long history. Its representatives expressed their thanks for the friendly reception and the good organization.

First Chairman Rudolf Sperner, his deputy Konrad Carl and board member Erwin Kastleiner then signed the city's Golden Book on behalf of their colleagues.