The genome assembly of Triticum aestivum cv. Chinese Spring (IWGSC RefSeq v1.0) was improved using optical maps constructed with the Nick Label Repair and Stain (NLRS) and Direct Label and Stain (DLS) Bionano optical mapping technologies. Optical maps were used to detect and resolve chimeric scaffolds, anchor unassigned scaffolds, correct ambiguities in positions and orientations of scaffolds, and in super-scaffolding. Contigs assembled from Chinese Spring whole-genome-shotgun (WGS) PacBio SMRT reads were employed in gap-closing. Pseudomolecules of the Chinese Spring 21 chromosomes were re-constructed. A total of 946 Mb of IWGSC RefSeq v1.0 assembly was revised: 92 chimeric scaffolds totaling 391.8 Mb were resolved, 312 scaffolds totaling 484.3 Mb were re-oriented, 227 previously unassigned scaffolds totaling 69.9 Mb were added. The number of gaps of unknown length was reduced from 4,021 to 650. Optical maps of diploid progenitors of the wheat A and D genomes, T. urartu and Aegilops tauschii, optical maps of tetraploid wild emmer (T. dicoccoides) and optical maps of T. aestivum were aligned. The alignments revealed structural changes among the genomes and subgenomes.