Our unfilled order position for our wholesale sales increased $133.5 million, or 68.4%, to $328.7 million at July 31, 2021, compared to $195.2 million at August 1, 2020. The increase in our backlog order levels reflects increased demand for product as our wholesale customers have placed more orders than last year due to the economic impact of the COVID-19 pandemic in the second quarter of 2020. In addition, the global supply chain disruptions have caused a delay in the receipt of inventory due to port congestion, reduced shipping vessel and container availability, and factory shutdowns as a result of the resurgence of COVID-19 infections. We are actively working with our suppliers to minimize these disruptions, but expect the disruptions to continue in the second half of 2021.
Gross Profit
Gross profit increased $30.9 million, or 48.3%, to $94.9 million for the second quarter of 2021, compared to $64.0 million for the second quarter of 2020, reflecting higher net sales and a higher gross profit rate. As a percentage of net sales, our gross profit increased to 39.7% for the second quarter of 2021, compared to 34.9% for the second quarter of 2020, reflecting more full price selling across our portfolio of brands driven by strong consumer demand. In connection with the supply chain disruptions described earlier and the related capacity shortages, our freight costs are rising. Though the impact was not significant during the second quarter, we anticipate higher inbound freight costs in the second half of 2021, which may impact our gross profit if we are unable to mitigate or recover these additional costs.
Gross profit increased $71.5 million, or 60.9%, to $188.9 million for the six months ended July 31, 2021, compared to $117.4 million for the six months ended August 1, 2020, due to higher net sales and improved gross profit rate. Our gross profit in the six months ended August 1, 2020 was impacted by higher incremental cost of goods sold primarily due to $27.5 million in inventory markdowns reflecting the difficult retail environment driven by the COVID pandemic, as well as $1.6 million in inventory markdowns related to the decision to exit our Fergie brand. As a percentage of net sales, our gross profit increased to 38.6% for the six months ended July 31, 2021, compared to 29.3% for the six months ended August 1, 2020.
Selling and Administrative Expenses
Selling and administrative expenses increased $4.8 million, or 6.5%, to $78.3 million for the second quarter of 2021, compared to $73.5 million for the second quarter of 2020. The increase was driven by higher salaries, due in part to the furloughs and temporary salary reductions in the second quarter of 2020 to mitigate the impact of COVID-19 on our financial results, and higher marketing expenses, partially offset by lower rent and facilities expenses, primarily associated with the lower store count. As a percentage of net sales, selling and administrative expenses decreased to 32.8% for the second quarter of 2021, compared to 40.1% for the second quarter of 2020.
Selling and administrative expenses decreased $4.5 million, or 2.7%, to $161.7 million for the six months ended July 31, 2021, compared to $166.2 million for the six months ended August 1, 2020. The decrease was driven by lower retail facilities costs, primarily associated with the lower store count, partially offset by higher marketing expenses. As a percentage of net sales, selling and administrative expenses decreased to 33.0% for the six months ended July 31, 2021, compared to 41.5% for the six months ended August 1, 2020.
Impairment of Goodwill and Intangible Assets
During the first quarter of 2020, we incurred impairment charges of $262.7 million, including $240.3 million associated with goodwill and $22.4 million associated with intangible assets, including $12.2 million for the Allen Edmonds trade name and $10.2 million for the Via Spiga trade name. There were no corresponding charges in the second quarter of 2020 or for the six months ended July 31, 2021. Refer to Note 5 and Note 8 to the condensed consolidated financial statements for further discussion of these charges.
Restructuring and Other Special Charges, Net
Restructuring and other special charges of $4.6 million were recorded during the second quarter of 2020, primarily for severance expense, with no corresponding charges for the second quarter of 2021. Restructuring and other special charges of $13.5 million were recorded during the six months ended July 31, 2021, reflecting expenses associated with the decision to close all but two flagship Naturalizer retail stores in the United States. These costs primarily represented lease termination and other store closure costs, including employee severance. For the six months ended August 1, 2020, we recorded restructuring and other special charges of $48.4 million, reflecting expenses associated with the impact of COVID-19 on our business operations, primarily impairment charges on store furniture and fixtures and lease right-of-use assets, liabilities due to our factories for order cancellations and severance. Refer to Note 5 to the condensed consolidated financial statements for additional information related to these charges.
Operating Earnings (Loss)
Operating earnings (loss) for the second quarter of 2021 exceeded pre-pandemic levels. Operating earnings increased $30.7 million to $16.6 million for the second quarter of 2021, compared to an operating loss of $14.1 million for the second quarter of 2020, as a result of the factors described above. As a percentage of net sales, operating earnings were 6.9% for the second quarter of 2021, compared to an operating loss of 7.7% in the second quarter of 2020.